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Synnatschke K, Moses Badlyan N, Wrzesińska A, Lozano Onrubia G, Hansen AL, Wolff S, Tornatzky H, Bensch W, Vaynzof Y, Maultzsch J, Backes C. Sonication-assisted liquid phase exfoliation of two-dimensional CrTe 3 under inert conditions. Ultrason Sonochem 2023; 98:106528. [PMID: 37506508 PMCID: PMC10407284 DOI: 10.1016/j.ultsonch.2023.106528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/09/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023]
Abstract
Liquid phase exfoliation (LPE) has been used for the successful fabrication of nanosheets from a large number of van der Waals materials. While this allows to study fundamental changes of material properties' associated with reduced dimensions, it also changes the chemistry of many materials due to a significant increase of the effective surface area, often accompanied with enhanced reactivity and accelerated oxidation. To prevent material decomposition, LPE and processing in inert atmosphere have been developed, which enables the preparation of pristine nanomaterials, and to systematically study compositional changes over time for different storage conditions. Here, we demonstrate the inert exfoliation of the oxidation-sensitive van der Waals crystal, CrTe3. The pristine nanomaterial was purified and size-selected by centrifugation, nanosheet dimensions in the fractions quantified by atomic force microscopy and studied by Raman, X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX) and photo spectroscopic measurements. We find a dependence of the relative intensities of the CrTe3 Raman modes on the propagation direction of the incident light, which prevents a correlation of the Raman spectral profile to the nanosheet dimensions. XPS and EDX reveal that the contribution of surface oxides to the spectra is reduced after exfoliation compared to the bulk material. Further, the decomposition mechanism of the nanosheets was studied by time-dependent extinction measurements after water titration experiments to initially dry solvents, which suggest that water plays a significant role in the material decomposition.
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Affiliation(s)
- Kevin Synnatschke
- Institute of Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany; School of Physics, University of Dublin, Trinity College, Dublin 2, Ireland
| | - Narine Moses Badlyan
- Institute for Solid-State Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany; Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen, Germany
| | - Angelika Wrzesińska
- Chair for Emerging Electronic Technologies, TU Dresden, Nöthnitzer Str. 61, Dresden, 01187 Sachsen, Germany; Leibniz-Institute for Solid State and Materials Research Dresden, Helmholtzstraße 20, Dresden 01069, Sachsen, Germany
| | - Guillermo Lozano Onrubia
- Institute of Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Anna-Lena Hansen
- Institute for Applied Materials-Energy Storage Systems (IAM-ESS), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein, Germany; Institute of Inorganic Chemistry, University of Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany
| | - Stefan Wolff
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen, Germany
| | - Hans Tornatzky
- Institute for Solid-State Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany; Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V, Hausvogteiplatz 5-7, 10117 Berlin, Germany
| | - Wolfgang Bensch
- Institute of Inorganic Chemistry, University of Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany
| | - Yana Vaynzof
- Chair for Emerging Electronic Technologies, TU Dresden, Nöthnitzer Str. 61, Dresden, 01187 Sachsen, Germany; Leibniz-Institute for Solid State and Materials Research Dresden, Helmholtzstraße 20, Dresden 01069, Sachsen, Germany
| | - Janina Maultzsch
- Institute for Solid-State Physics, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany; Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen, Germany
| | - Claudia Backes
- Chair of Physical Chemistry of Nanomaterials, University of Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany.
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Shcherbakov A, Synnatschke K, Bodnar S, Zerhoch J, Eyre L, Rauh F, Heindl MW, Liu S, Konecny J, Sharp ID, Sofer Z, Backes C, Deschler F. Solution-Processed NiPS 3 Thin Films from Liquid Exfoliated Inks with Long-Lived Spin-Entangled Excitons. ACS Nano 2023. [PMID: 37220255 DOI: 10.1021/acsnano.3c01119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Antiferromagnets are promising materials for future opto-spintronic applications since they show spin dynamics in the THz range and no net magnetization. Recently, layered van der Waals (vdW) antiferromagnets have been reported, which combine low-dimensional excitonic properties with complex spin-structure. While various methods for the fabrication of vdW 2D crystals exist, formation of large area and continuous thin films is challenging because of either limited scalability, synthetic complexity, or low opto-spintronic quality of the final material. Here, we fabricate centimeter-scale thin films of the van der Waals 2D antiferromagnetic material NiPS3, which we prepare using a crystal ink made from liquid phase exfoliation (LPE). We perform statistical atomic force microscopy (AFM) and scanning electron microscopy (SEM) to characterize and control the lateral size and number of layers through this ink-based fabrication. Using ultrafast optical spectroscopy at cryogenic temperatures, we resolve the dynamics of photoexcited excitons. We find antiferromagnetic spin arrangement and spin-entangled Zhang-Rice multiplet excitons with lifetimes in the nanosecond range, as well as ultranarrow emission line widths, despite the disordered nature of our films. Thus, our findings demonstrate scalable thin-film fabrication of high-quality NiPS3, which is crucial for translating this 2D antiferromagnetic material into spintronic and nanoscale memory devices and further exploring its complex spin-light coupled states.
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Affiliation(s)
- Andrii Shcherbakov
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Kevin Synnatschke
- School of Physics, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Stanislav Bodnar
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Jonathan Zerhoch
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Lissa Eyre
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
- Electrical Engineering Division, University of Cambridge, 9 JJ Thomson Ave, Cambridge CB3 0FA, United Kingdom
| | - Felix Rauh
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Markus W Heindl
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Shangpu Liu
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Jan Konecny
- Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Ian D Sharp
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Zdeněk Sofer
- Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Claudia Backes
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
- Physical Chemistry of Nanomaterials, University of Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Felix Deschler
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
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Li Z, Rashvand F, Bretscher H, Szydłowska BM, Xiao J, Backes C, Rao A. Understanding the Photoluminescence Quenching of Liquid Exfoliated WS 2 Monolayers. J Phys Chem C Nanomater Interfaces 2022; 126:21681-21688. [PMID: 36605783 PMCID: PMC9806825 DOI: 10.1021/acs.jpcc.2c05284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 11/24/2022] [Indexed: 06/17/2023]
Abstract
Monolayer transition metal dichalcogenides (TMDs) are being investigated as active materials in optoelectronic devices due to their strong excitonic effects. While mechanical exfoliation (ME) of monolayer TMDs is limited to small areas, these materials can also be exfoliated from their parent layered materials via high-volume liquid phase exfoliation (LPE). However, it is currently considered that LPE-synthesized materials show poor optoelectronic performance compared to ME materials, such as poor photoluminescence quantum efficiencies (PLQEs). Here we evaluate the photophysical properties of monolayer-enriched LPE WS2 dispersions via steady-state and time-resolved optical spectroscopy and benchmark these materials against untreated and chemically treated ME WS2 monolayers. We show that the LPE materials show features of high-quality semiconducting materials such as very small Stokes shift, smaller photoluminescence line widths, and longer exciton lifetimes than ME WS2. We reveal that the energy transfer between the direct-gap monolayers and in-direct gap few-layers in LPE WS2 dispersions is a major reason for their quenched PL. Our results suggest that LPE TMDs are not inherently highly defective and could have a high potential for optoelectronic device applications if improved strategies to purify the LPE materials and reduce aggregation could be implemented.
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Affiliation(s)
- Zhaojun Li
- Cavendish
Laboratory, University of Cambridge, JJ Thomson Avenue, CB3 0HE Cambridge, United Kingdom
- Molecular
and Condensed Matter Physics, Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden
| | - Farnia Rashvand
- Institute
for Physical Chemistry, Ruprecht-Karls-Universität
Heidelberg, Im Neuenheimer
Feld 253, 69120 Heidelberg, Germany
| | - Hope Bretscher
- Cavendish
Laboratory, University of Cambridge, JJ Thomson Avenue, CB3 0HE Cambridge, United Kingdom
| | - Beata M. Szydłowska
- Institute
for Physical Chemistry, Ruprecht-Karls-Universität
Heidelberg, Im Neuenheimer
Feld 253, 69120 Heidelberg, Germany
| | - James Xiao
- Cavendish
Laboratory, University of Cambridge, JJ Thomson Avenue, CB3 0HE Cambridge, United Kingdom
| | - Claudia Backes
- Institute
for Physical Chemistry, Ruprecht-Karls-Universität
Heidelberg, Im Neuenheimer
Feld 253, 69120 Heidelberg, Germany
| | - Akshay Rao
- Cavendish
Laboratory, University of Cambridge, JJ Thomson Avenue, CB3 0HE Cambridge, United Kingdom
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Gosch J, Synnatschke K, Stock N, Backes C. Comparative study of sonication-assisted liquid phase exfoliation of six layered coordination polymers. Chem Commun (Camb) 2022; 59:55-58. [PMID: 36503965 DOI: 10.1039/d2cc03366f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sonication-assisted liquid phase exfoliation was applied to six different layered coordination polymers (CPs) in aqueous surfactant solution. The resulting nanosheets were investigated for structural and compositional integrity and microscopic analysis gives insights into the relationship between the crystal structure of the materials and their exfoliability. Larger open pores seem to favour the production of nanosheets with higher aspect ratio of lateral size to thickness.
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Affiliation(s)
- Jonas Gosch
- Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, Kiel 24118, Germany
| | - Kevin Synnatschke
- University of Dublin, Trinity College, Dublin 2, SNIAM Building, Ireland
| | - Norbert Stock
- Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, Kiel 24118, Germany
| | - Claudia Backes
- University of Kassel, Heinrich-Plett-Str. 40, Kassel D-34132, Germany
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Rezende P, Rodrigues L, Backes C, Teodoro A, Santos A, Fernandes P, Giongo P, Ribon A, Bessa S. Productivity and nutrient extraction by Paiaguás palisadegrass, single and intercropping with pigeon pea, submitted to doses of nitrogen. ARQ BRAS MED VET ZOO 2022. [DOI: 10.1590/1678-4162-12827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
ABSTRACT The objective of this work was to evaluate the productivity and extraction of macronutrients by Urochloa brizantha cv. BRS Paiaguás (Syn. Brachiaria brizantha cv. BRS Paiaguás) single and intercropped with pigeon pea (Cajanus cajan cv. BRS Mandarim), subjected to four doses of nitrogen applied in topdressing (0, 80, 160 and 240 kg ha-1). The experiment was carried out in São Luís de Montes Belos, GO, in soil classified as dystrophic red latosol, under Cerrado conditions. Plant height and dry mass of pigeon pea, plant height, number of tillers, dry mass, and macronutrient extraction by Paiaguás palisadegrass were evaluated. Higher mass production was observed in the pasture intercropped with the legume, requiring a lower amount of N. Based on the results exposed, the cultivation of Paiaguás palisadegrass reaches higher productivity when intercropped with a legume such as pigeon pea, in addition to providing greater efficiency in the use of nutrients such as N, P and K. Nitrogen fertilization has a negative influence on the production of dry mass and height of pigeon pea plants.
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Affiliation(s)
| | | | - C. Backes
- Universidade Estadual de Goiás, Brazil
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Ersu G, Kuriakose S, Goldie SJ, Al-Enizi AM, Nafady A, Munuera C, Backes C, Island JO, Castellanos-Gomez A. Improving the conductivity of graphite-based films by rapid laser annealing. Nanoscale Adv 2022; 4:4724-4729. [PMID: 36545390 PMCID: PMC9642606 DOI: 10.1039/d2na00557c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 09/20/2022] [Indexed: 06/17/2023]
Abstract
We present a method to anneal devices based on graphite films on paper and polycarbonate substrates. The devices are created using four different methods: spray-on films, graphite pencil-drawn films, liquid-phase exfoliated graphite films, and graphite powder abrasion-applied films. We characterize the optical properties of the films before and after laser annealing and report the two-terminal resistance of the devices for increased laser power density. We find the greatest improvement (16× reduction) in the resistance of spray-on film devices starting from 25.0 kΩ and reaching 1.6 kΩ at the highest annealing power densities. These improvements are attributed to local laser ablation of binders, stabilizers, and solvent residues left in the film after fabrication. This work highlights the utility of focused laser annealing for spray-on, drawn, printed, and abrasion fabricated films on substrates sensitive to heat/thermal treatments.
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Affiliation(s)
- Gulsum Ersu
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) Madrid E-28049 Spain
| | - Sruthi Kuriakose
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) Madrid E-28049 Spain
| | - Stuart J Goldie
- Physical Chemistry of Nanomaterials, University of Kassel Germany
| | - Abdullah M Al-Enizi
- Department of Chemistry, College of Science, King Saud University Riyadh 11451 Saudi Arabia
| | - Ayman Nafady
- Department of Chemistry, College of Science, King Saud University Riyadh 11451 Saudi Arabia
| | - Carmen Munuera
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) Madrid E-28049 Spain
| | - Claudia Backes
- Physical Chemistry of Nanomaterials, University of Kassel Germany
| | - Joshua O Island
- Department of Physics and Astronomy, University of Nevada Las Vegas Las Vegas NV 89154 USA
| | - Andres Castellanos-Gomez
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) Madrid E-28049 Spain
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Oliveira L, Taveira J, Fernandes P, Backes C, Costa C, Santos A, Gurgel A, Ribeiro A, Rodrigues L, Teodoro A. Use of blood residue as alternative source of phosphorus in sunflower (Helianthus annuus L.) cultivation. ARQ BRAS MED VET ZOO 2022. [DOI: 10.1590/1678-4162-12448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ABSTRACT The aim of this work was to increase the aerial part, biometry, and yield of achenes from sunflower plants on the effect of increasing doses of blood residue, as an alternative source of phosphorus (P), in a clayey-textured red Oxisol. The experimental design used was randomized blocks, with six treatments and four replications. The treatments consisted of five doses of blood residue (0, 6, 12, 24 and 48m3 ha-1) and a control treatment that received phosphate chemical fertilization, 80kg ha-1 of P2O5. The increasing doses of blood residue and chemical fertilization do not show disproportionality for P concentration in soil, leaf, plant height (PH), stem diameter (SD), chapter diameter (CD) and achene production. The analysis of the principal component (PC) revealed that the first PC presents the greatest accumulated variation (74%). Based on the first PC, the dose of 12m-3 ha-1 has greater influence for PH, SC, and CD. Due to the greater influence on the biometric characteristics of sunflower plants, the blood residue (12m-3 ha-1 = 98.4kg P ha-1), can be used as an alternative source of phosphorus for the cultivation of sunflower in clayey oxisols.
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Affiliation(s)
| | | | | | - C. Backes
- Universidade Estadual de Goiás, Brazil
| | - C.M. Costa
- Universidade Federal de Mato Grosso do Sul, Brazil
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Rao VJ, Qi H, Berger FJ, Grieger S, Kaiser U, Backes C, Zaumseil J. Liquid Phase Exfoliation of Rubrene Single Crystals into Nanorods and Nanobelts. ACS Nano 2021; 15:20466-20477. [PMID: 34813291 DOI: 10.1021/acsnano.1c08965] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Liquid phase exfoliation (LPE) is a popular method to create dispersions of two-dimensional nanosheets from layered inorganic van der Waals crystals. Here, it is applied to orthorhombic and triclinic single crystals of the organic semiconductor rubrene with only noncovalent interactions (mainly π-π) between the molecules. Distinct nanorods and nanobelts of rubrene are formed, stabilized against aggregation in aqueous sodium cholate solution, and isolated by liquid cascade centrifugation. Selected-area electron diffraction and Raman spectroscopy confirm the crystallinity of the rubrene nanorods and nanobelts while the optical properties (absorbance, photoluminescence) of the dispersions are similar to rubrene solutions due to their randomized orientations. The formation of these stable crystalline rubrene nanostructures with only a few molecular layers by LPE confirms that noncovalent interactions in molecular crystals can be strong enough to enable mechanical exfoliation similar to inorganic layered materials.
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Affiliation(s)
- Vaishnavi J Rao
- Institute for Physical Chemistry, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Haoyuan Qi
- Central Facility of Materials Science Electron Microscopy, Universität Ulm, 89081 Ulm, Germany
- Center for Advancing Electronics Dresden & Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany
| | - Felix J Berger
- Institute for Physical Chemistry, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Sebastian Grieger
- Institute for Physical Chemistry, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Ute Kaiser
- Central Facility of Materials Science Electron Microscopy, Universität Ulm, 89081 Ulm, Germany
| | - Claudia Backes
- Institute for Physical Chemistry, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Jana Zaumseil
- Institute for Physical Chemistry, Universität Heidelberg, D-69120 Heidelberg, Germany
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Sudhindra S, Rashvand F, Wright D, Barani Z, Drozdov AD, Baraghani S, Backes C, Kargar F, Balandin AA. Specifics of Thermal Transport in Graphene Composites: Effect of Lateral Dimensions of Graphene Fillers. ACS Appl Mater Interfaces 2021; 13:53073-53082. [PMID: 34705408 DOI: 10.1021/acsami.1c15346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report on the investigation of thermal transport in noncured silicone composites with graphene fillers of different lateral dimensions. Graphene fillers are comprised of few-layer graphene flakes with lateral sizes in the range from 400 to 1200 nm and the number of atomic planes from 1 to ∼100. The distribution of the lateral dimensions and thicknesses of graphene fillers has been determined via atomic force microscopy statistics. It was found that in the examined range of the lateral dimensions, the thermal conductivity of the composites increases with increasing size of the graphene fillers. The observed difference in thermal properties can be related to the average gray phonon mean free path in graphene, which has been estimated to be around ∼800 nm at room temperature. The thermal contact resistance of composites with graphene fillers of 1200 nm lateral dimensions was also smaller than that of composites with graphene fillers of 400 nm lateral dimensions. The effects of the filler loading fraction and the filler size on the thermal conductivity of the composites were rationalized within the Kanari model. The obtained results are important for the optimization of graphene fillers for applications in thermal interface materials for heat removal from high-power-density electronics.
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Affiliation(s)
- Sriharsha Sudhindra
- Phonon Optimized Engineered Materials Center, University of California, Riverside, California 92521, United States
- Department of Electrical and Computer Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
| | - Farnia Rashvand
- Institute of Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, Heidelberg 69120, Germany
| | - Dylan Wright
- Phonon Optimized Engineered Materials Center, University of California, Riverside, California 92521, United States
- Department of Electrical and Computer Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
| | - Zahra Barani
- Phonon Optimized Engineered Materials Center, University of California, Riverside, California 92521, United States
- Department of Electrical and Computer Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
| | - Aleksey D Drozdov
- Department of Materials and Production, Aalborg University, Fibigerstraede 16, Aalborg 9220, Denmark
| | - Saba Baraghani
- Phonon Optimized Engineered Materials Center, University of California, Riverside, California 92521, United States
- Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Claudia Backes
- Institute of Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, Heidelberg 69120, Germany
| | - Fariborz Kargar
- Phonon Optimized Engineered Materials Center, University of California, Riverside, California 92521, United States
- Department of Electrical and Computer Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
- Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Alexander A Balandin
- Phonon Optimized Engineered Materials Center, University of California, Riverside, California 92521, United States
- Department of Electrical and Computer Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, United States
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10
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Karger L, Synnatschke K, Settele S, Hofstetter YJ, Nowack T, Zaumseil J, Vaynzof Y, Backes C. The Role of Additives in Suppressing the Degradation of Liquid-Exfoliated WS 2 Monolayers. Adv Mater 2021; 33:e2102883. [PMID: 34477255 DOI: 10.1002/adma.202102883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/16/2021] [Indexed: 06/13/2023]
Abstract
Group VI transition metal dichalcogenides (TMDs) are considered to be chemically widely inert, but recent reports point toward an oxidation of monolayered sheets in ambient conditions, due to defects. To date, the degradation of monolayered TMDs is only studied on individual, substrate-supported nanosheets with varying defect type and concentration, strain, and in an inhomogeneous environment. Here, degradation kinetics of WS2 nanosheet ensembles in the liquid phase are investigated through photoluminescence measurements, which selectively probe the monolayers. Monolayer-enriched WS2 dispersions are produced with varying lateral sizes in the two common surfactant stabilizers sodium cholate (SC) and sodium dodecyl sulfate (SDS). Well-defined degradation kinetics are observed, which enable the determination of activation energies of the degradation and decouple photoinduced and thermal degradation. The thermal degradation is slower than the photoinduced degradation and requires higher activation energy. Using SC as surfactant, it is sufficiently suppressed. The photoinduced degradation can be widely prevented through chemical passivation achieved through the addition of cysteine which, on the one hand, coordinates to defects on the nanosheets and, on the other hand, stabilizes oxides on the surface, which shield the nanosheets from further degradation.
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Affiliation(s)
- Leonhard Karger
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Kevin Synnatschke
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Simon Settele
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Yvonne J Hofstetter
- Integrated Center for Applied Photophysics and Photonic Materials, TU Dresden, Nöthnitzer Straße 61, 01187, Dresden, Germany
- Center for Advancing Electronics Dresden (cfaed), TU Dresden, Helmhotzstraße 18, 01069, Dresden, Germany
| | - Tim Nowack
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Jana Zaumseil
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
- Centre for Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Yana Vaynzof
- Integrated Center for Applied Photophysics and Photonic Materials, TU Dresden, Nöthnitzer Straße 61, 01187, Dresden, Germany
- Center for Advancing Electronics Dresden (cfaed), TU Dresden, Helmhotzstraße 18, 01069, Dresden, Germany
| | - Claudia Backes
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
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11
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Kaur H, Tian R, Roy A, McCrystall M, Horvath DV, Onrubia GL, Smith R, Ruether M, Griffin A, Backes C, Nicolosi V, Coleman JN. Correction to Production of Quasi-2D Platelets of Nonlayered Iron Pyrite (FeS 2) by Liquid-Phase Exfoliation for High Performance Battery Electrodes. ACS Nano 2021; 15:9196. [PMID: 33950685 DOI: 10.1021/acsnano.1c03538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
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12
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Ott S, Lakmann M, Backes C. Impact of Pretreatment of the Bulk Starting Material on the Efficiency of Liquid Phase Exfoliation of WS 2. Nanomaterials (Basel) 2021; 11:nano11051072. [PMID: 33921953 PMCID: PMC8143503 DOI: 10.3390/nano11051072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 12/16/2022]
Abstract
Liquid phase exfoliation (LPE) is widely used to produce colloidal dispersions of nanomaterials, in particular two-dimensional nanosheets. The degree of exfoliation, i.e., the length to thickness aspect ratio was shown to be intrinsically limited by the ratio of in-plane to out-of-plane binding strength. In this work, we investigate whether simple pretreatment of the starting material can be used to change the in-plane to out-of-plane binding strength through mild intercalation to improve the sample quality in sonication-assisted LPE. Five different pretreatment conditions of WS2 were tested and the dispersions size-selected through centrifugation. From optical spectroscopy (extinction, Raman, photoluminescence), information on nanosheet dimension (average lateral size, layer number, monolayer size) and optical quality (relative photoluminescence quantum yield) was extracted. We find that the pretreatment has a minor impact on the length/thickness aspect ratio, but that photoluminescence quantum yield can be increased in particular using mild sonication conditions. We attribute this to the successful exfoliation of nanosheets with a lower degree of basal plane defectiveness. This work emphasizes the complexity of the exfoliation process and suggests that the role of defects has to be considered for a comprehensive picture.
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13
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Backes C, Bartus S, Casiraghi C, Ferrari A, Kamali AR, Kolíbal M, Kumar V, Molle A, Oyarzun A, Palermo V, Sengupta A, Silvestri A, Zhang H. Applications in opto-electronics: general discussion. Faraday Discuss 2021; 227:184-188. [PMID: 33877207 DOI: 10.1039/d1fd90006d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Backes C, Bianco A, Casiraghi C, Galembeck F, Gupta RK, Hersam MC, Kamali AR, Kolíbal M, Kolosov V, Kumar V, Lee WH, Martsinovich N, Melchionna M, Müllen K, Oyarzun A, Palermo V, Prato M, Samori P, Sampath S, Silvestri A, Sirbu D, Sui R, Turchanin A, Wetzl C, Wright IA, Xia Z, Zhuang X. 2D materials production and generation of functional inks: general discussion. Faraday Discuss 2021; 227:141-162. [PMID: 33877206 DOI: 10.1039/d1fd90002a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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15
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Backes C, Behera RK, Bianco A, Casiraghi C, Doan H, Criado A, Galembeck F, Goldie S, Gravagnuolo AM, Hou HL, Kamali AR, Kostarelos K, Kumar V, Lee WH, Martsinovich N, Palermo V, Palma M, Pang J, Prato M, Samori P, Silvestri A, Singh S, Strano M, Wetzl C. Biomedical applications: general discussion. Faraday Discuss 2021; 227:245-258. [PMID: 33877208 DOI: 10.1039/d1fd90003j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Backes C, Behera RK, Bellamy-Carter A, Bianco A, Caps V, Casiraghi C, Chhowalla M, Criado A, Davies T, Ferrari AC, Fornasaro S, Galembeck F, Goldie S, Hersam MC, Kamali AR, Kolosov V, Kumar V, Lee WH, Martsinovich N, Melchionna M, Melucci M, Molle A, Morgan H, Neumann C, Nowack T, Oyarzun A, Palermo V, Papanai GS, Prato M, Shin Y, Sui R, Teixeira IF, Wang G, Xia Z. 3-Dimensional graphene-like structures and applications: general discussion. Faraday Discuss 2021; 227:359-382. [PMID: 33877209 DOI: 10.1039/d1fd90007b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Mansour N, Backes C, Becker C, Hofauer B, Knopf A. [Clear resection margins to avoid escalation of adjuvant therapy in oropharyngeal squamous cell carcinoma]. HNO 2021; 69:256-262. [PMID: 32975607 PMCID: PMC7997822 DOI: 10.1007/s00106-020-00932-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Resection margins in patients with oropharyngeal squamous cell carcinoma (OPSCC) are a predictive marker for overall survival (OS) and recurrence-free interval (RFI). Adjuvant therapy is influenced by TNM status, extracapsular extension (ECE), and resection margin status (R) of the primary tumor. The R status can be directly influenced by the head and neck surgeon. The aim of the current study was to evaluate the impact of R status on treatment decisions, RFI, and OS. MATERIALS AND METHODS All patients with OPSCC who underwent surgery (with/without adjuvant therapy) between 2001 and 2011 were enrolled. Clinical data, survival parameters, histologic data such as ECE, resection margin status, and tumor size were retrospectively collected and analyzed. RESULTS A total of 208 patients were enrolled. Survival parameters showed that patients with microscopically clear (R0) resection margins had an RFI/OS of 89/87 months. These values decreased in patients with R1 (65/65 months), R2 (38/33 months), and Rx (unclear) resections (59/45 months; p = 0.036/p = 0.001). In patients with ECE and R1 resection, but also in those with R0 resections achieved by follow-up resection and those with Rx resections, adjuvant therapy was escalated. CONCLUSION Unclear resection status reduces OS and RFI in patients with OPSCC. Therefore, in surgical therapy, clear resection status in the first pass should be strived for to avoid escalation of adjuvant therapy due to an unclear R status.
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Affiliation(s)
- N Mansour
- Klinik für Hals, Nasen- und Ohrenheilkunde, Universitätsklinikum Freiburg, Killianstr. 5, 79106, Freiburg, Deutschland.
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenheilkunde, Klinikum rechts der Isar, Technische Universität München, München, Deutschland.
| | - C Backes
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenheilkunde, Klinikum rechts der Isar, Technische Universität München, München, Deutschland
| | - C Becker
- Klinik für Hals, Nasen- und Ohrenheilkunde, Universitätsklinikum Freiburg, Killianstr. 5, 79106, Freiburg, Deutschland
| | - B Hofauer
- Klinik für Hals, Nasen- und Ohrenheilkunde, Universitätsklinikum Freiburg, Killianstr. 5, 79106, Freiburg, Deutschland
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenheilkunde, Klinikum rechts der Isar, Technische Universität München, München, Deutschland
| | - A Knopf
- Klinik für Hals, Nasen- und Ohrenheilkunde, Universitätsklinikum Freiburg, Killianstr. 5, 79106, Freiburg, Deutschland
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenheilkunde, Klinikum rechts der Isar, Technische Universität München, München, Deutschland
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18
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Kaur H, Tian R, Roy A, McCrystall M, Horvath DV, Lozano Onrubia G, Smith R, Ruether M, Griffin A, Backes C, Nicolosi V, Coleman JN. Production of Quasi-2D Platelets of Nonlayered Iron Pyrite (FeS 2) by Liquid-Phase Exfoliation for High Performance Battery Electrodes. ACS Nano 2020; 14:13418-13432. [PMID: 32960568 DOI: 10.1021/acsnano.0c05292] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Over the past 15 years, two-dimensional (2D) materials have been studied and exploited for many applications. In many cases, 2D materials are formed by the exfoliation of layered crystals such as transition-metal disulfides. However, it has recently become clear that it is possible to exfoliate nonlayered materials so long as they have a nonisotropic bonding arrangement. Here, we report the synthesis of 2D-platelets from the earth-abundant, nonlayered metal sulfide, iron pyrite (FeS2), using liquid-phase exfoliation. The resultant 2D platelets exhibit the same crystal structure as bulk pyrite but are surface passivated with a density of 14 × 1018 groups/m2. They form stable suspensions in common solvents and can be size-selected and liquid processed. Although the platelets have relatively low aspect ratios (∼5), this is in line with the anisotropic cleavage energy of bulk FeS2. We observe size-dependent changes to optical properties leading to spectroscopic metrics that can be used to estimate the dimensions of platelets. These platelets can be used to produce lithium ion battery anodes with capacities approaching 1000 mAh/g.
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Affiliation(s)
- Harneet Kaur
- CRANN & AMBER Research Centres, Trinity College Dublin, Dublin, D2, Ireland
- School of Physics, Trinity College Dublin, Dublin, D2, Ireland
| | - Ruiyuan Tian
- CRANN & AMBER Research Centres, Trinity College Dublin, Dublin, D2, Ireland
- School of Physics, Trinity College Dublin, Dublin, D2, Ireland
| | - Ahin Roy
- School of Chemistry, Trinity College Dublin, Dublin, D2, Ireland
| | - Mark McCrystall
- CRANN & AMBER Research Centres, Trinity College Dublin, Dublin, D2, Ireland
- School of Physics, Trinity College Dublin, Dublin, D2, Ireland
| | - Dominik Valter Horvath
- CRANN & AMBER Research Centres, Trinity College Dublin, Dublin, D2, Ireland
- School of Physics, Trinity College Dublin, Dublin, D2, Ireland
| | - Guillermo Lozano Onrubia
- Chair of Applied Physical Chemistry, Ruprecht-Karls University Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Ross Smith
- CRANN & AMBER Research Centres, Trinity College Dublin, Dublin, D2, Ireland
- School of Physics, Trinity College Dublin, Dublin, D2, Ireland
| | - Manuel Ruether
- School of Chemistry, Trinity College Dublin, Dublin, D2, Ireland
| | - Aideen Griffin
- CRANN & AMBER Research Centres, Trinity College Dublin, Dublin, D2, Ireland
- School of Physics, Trinity College Dublin, Dublin, D2, Ireland
| | - Claudia Backes
- Chair of Applied Physical Chemistry, Ruprecht-Karls University Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Valeria Nicolosi
- CRANN & AMBER Research Centres, Trinity College Dublin, Dublin, D2, Ireland
- School of Chemistry, Trinity College Dublin, Dublin, D2, Ireland
| | - Jonathan N Coleman
- CRANN & AMBER Research Centres, Trinity College Dublin, Dublin, D2, Ireland
- School of Physics, Trinity College Dublin, Dublin, D2, Ireland
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19
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Li Z, Young RJ, Backes C, Zhao W, Zhang X, Zhukov AA, Tillotson E, Conlan AP, Ding F, Haigh SJ, Novoselov KS, Coleman JN. Mechanisms of Liquid-Phase Exfoliation for the Production of Graphene. ACS Nano 2020; 14:10976-10985. [PMID: 32598132 DOI: 10.1021/acsnano.0c03916] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Liquid- phase exfoliation (LPE) is the principal method of producing two-dimensional (2D) materials such as graphene in large quantities with a good balance between quality and cost and is now widely adopted by both the academic and industrial sectors. The fragmentation and exfoliation mechanisms involved have usually been simply attributed to the force induced by ultrasound and the interaction with the solvent molecules. Nonetheless, little is known about how they actually occur, i.e., how thick and large graphite crystals can be exfoliated into thin and small graphene flakes. Here, we demonstrate that during ultrasonic LPE the transition from graphite flakes to graphene takes place in three distinct stages. First, sonication leads to the rupture of large flakes and the formation of kink band striations on the flake surfaces, primarily along zigzag directions. Second, cracks form along these striations, and together with intercalation of solvent, lead to the unzipping and peeling off of thin graphite strips that in the final stage are exfoliated into graphene. The findings will be of great value in the quest to optimize the lateral dimensions, thickness, and yield of graphene and other 2D materials in large-scale LPE for various applications.
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Affiliation(s)
- Zheling Li
- Department of Materials, University of Manchester, Manchester M13 9PL, U.K
- National Graphene Institute, University of Manchester, Manchester M13 9PL, U.K
| | - Robert J Young
- Department of Materials, University of Manchester, Manchester M13 9PL, U.K
- National Graphene Institute, University of Manchester, Manchester M13 9PL, U.K
- Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Claudia Backes
- Institute of Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Wen Zhao
- Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hung Hom, Hong Kong
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS-CMCM)/School of Material Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Xun Zhang
- Department of Materials, University of Manchester, Manchester M13 9PL, U.K
| | - Alexander A Zhukov
- National Graphene Institute, University of Manchester, Manchester M13 9PL, U.K
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Evan Tillotson
- Department of Materials, University of Manchester, Manchester M13 9PL, U.K
- National Graphene Institute, University of Manchester, Manchester M13 9PL, U.K
| | - Aidan P Conlan
- Department of Materials, University of Manchester, Manchester M13 9PL, U.K
- National Graphene Institute, University of Manchester, Manchester M13 9PL, U.K
| | - Feng Ding
- Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hung Hom, Hong Kong
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS-CMCM)/School of Material Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Sarah J Haigh
- Department of Materials, University of Manchester, Manchester M13 9PL, U.K
- National Graphene Institute, University of Manchester, Manchester M13 9PL, U.K
| | - Kostya S Novoselov
- National Graphene Institute, University of Manchester, Manchester M13 9PL, U.K
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
- Chongqing 2D Materials Institute, Liangjiang New Area, Chongqing 400714, China
| | - Jonathan N Coleman
- School of Physics and CRANN & AMBER Research Centers, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
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20
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Leubner S, Bengtsson VEG, Synnatschke K, Gosch J, Koch A, Reinsch H, Xu H, Backes C, Zou X, Stock N. Synthesis and Exfoliation of a New Layered Mesoporous Zr-MOF Comprising Hexa- and Dodecanuclear Clusters as Well as a Small Organic Linker Molecule. J Am Chem Soc 2020; 142:15995-16000. [DOI: 10.1021/jacs.0c06978] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Sebastian Leubner
- Institute of Inorganic Chemistry, University of Kiel, Max-Eyth Strasse 2, 24118 Kiel, Germany
| | - Viktor E. G. Bengtsson
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Kevin Synnatschke
- Institute of Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Jonas Gosch
- Institute of Inorganic Chemistry, University of Kiel, Max-Eyth Strasse 2, 24118 Kiel, Germany
| | - Alexander Koch
- Institute of Inorganic Chemistry, University of Kiel, Max-Eyth Strasse 2, 24118 Kiel, Germany
| | - Helge Reinsch
- Institute of Inorganic Chemistry, University of Kiel, Max-Eyth Strasse 2, 24118 Kiel, Germany
| | - Hongyi Xu
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Claudia Backes
- Institute of Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Xiaodong Zou
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Norbert Stock
- Institute of Inorganic Chemistry, University of Kiel, Max-Eyth Strasse 2, 24118 Kiel, Germany
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21
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Grieger S, Szydłowska BM, Rao VJ, Steinmann E, Dodds M, Gholamvand Z, Duesberg GS, Zaumseil J, Backes C. Titelbild: Site‐Selective Oxidation of Monolayered Liquid‐Exfoliated WS
2
by Shielding the Basal Plane through Adsorption of a Facial Amphiphile (Angew. Chem. 33/2020). Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202007849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sebastian Grieger
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Beata M. Szydłowska
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
- Institute of Physics, EIT 2 Faculty of Electrical Engineering and Information Technology Universität der Bundeswehr München Werner-Heisenberg-Weg 39 85577 Neubiberg Germany
| | - Vaishnavi J. Rao
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Eva Steinmann
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Marcus Dodds
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Zahra Gholamvand
- School of Physics and CRANN & AMBER Research Centres Trinity College Dublin Dublin 2 Ireland
| | - Georg S. Duesberg
- Institute of Physics, EIT 2 Faculty of Electrical Engineering and Information Technology Universität der Bundeswehr München Werner-Heisenberg-Weg 39 85577 Neubiberg Germany
| | - Jana Zaumseil
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
- Centre for Advanced Materials Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 225 69120 Heidelberg Germany
| | - Claudia Backes
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
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22
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Grieger S, Szydłowska BM, Rao VJ, Steinmann E, Dodds M, Gholamvand Z, Duesberg GS, Zaumseil J, Backes C. Site-Selective Oxidation of Monolayered Liquid-Exfoliated WS 2 by Shielding the Basal Plane through Adsorption of a Facial Amphiphile. Angew Chem Int Ed Engl 2020; 59:13785-13792. [PMID: 32449582 PMCID: PMC7496821 DOI: 10.1002/anie.202005730] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Indexed: 12/31/2022]
Abstract
In recent years, various functionalization strategies for transition‐metal dichalcogenides have been explored to tailor the properties of materials and to provide anchor points for the fabrication of hybrid structures. Herein, new insights into the role of the surfactant in functionalization reactions are described. Using the spontaneous reaction of WS2 with chloroauric acid as a model reaction, the regioselective formation of gold nanoparticles on WS2 is shown to be heavily dependent on the surfactant employed. A simple model is developed to explain the role of the chosen surfactant in this heterogeneous functionalization reaction. The surfactant coverage is identified as the crucial element that governs the dominant reaction pathway and therefore can severely alter the reaction outcome. This study shows the general importance of the surfactant choice and how detrimental or beneficial a certain surfactant can be to the desired functionalization.
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Affiliation(s)
- Sebastian Grieger
- Institute for Physical Chemistry, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Beata M Szydłowska
- Institute for Physical Chemistry, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany.,Institute of Physics, EIT 2, Faculty of Electrical Engineering and Information Technology, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577, Neubiberg, Germany
| | - Vaishnavi J Rao
- Institute for Physical Chemistry, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Eva Steinmann
- Institute for Physical Chemistry, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Marcus Dodds
- Institute for Physical Chemistry, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Zahra Gholamvand
- School of Physics and CRANN & AMBER Research Centres, Trinity College Dublin, Dublin, 2, Ireland
| | - Georg S Duesberg
- Institute of Physics, EIT 2, Faculty of Electrical Engineering and Information Technology, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577, Neubiberg, Germany
| | - Jana Zaumseil
- Institute for Physical Chemistry, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany.,Centre for Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Claudia Backes
- Institute for Physical Chemistry, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
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23
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Grieger S, Szydłowska BM, Rao VJ, Steinmann E, Dodds M, Gholamvand Z, Duesberg GS, Zaumseil J, Backes C. Cover Picture: Site‐Selective Oxidation of Monolayered Liquid‐Exfoliated WS
2
by Shielding the Basal Plane through Adsorption of a Facial Amphiphile (Angew. Chem. Int. Ed. 33/2020). Angew Chem Int Ed Engl 2020. [DOI: 10.1002/anie.202007849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Sebastian Grieger
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Beata M. Szydłowska
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
- Institute of Physics, EIT 2 Faculty of Electrical Engineering and Information Technology Universität der Bundeswehr München Werner-Heisenberg-Weg 39 85577 Neubiberg Germany
| | - Vaishnavi J. Rao
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Eva Steinmann
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Marcus Dodds
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Zahra Gholamvand
- School of Physics and CRANN & AMBER Research Centres Trinity College Dublin Dublin 2 Ireland
| | - Georg S. Duesberg
- Institute of Physics, EIT 2 Faculty of Electrical Engineering and Information Technology Universität der Bundeswehr München Werner-Heisenberg-Weg 39 85577 Neubiberg Germany
| | - Jana Zaumseil
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
- Centre for Advanced Materials Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 225 69120 Heidelberg Germany
| | - Claudia Backes
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
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24
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Jurewicz I, King AAK, Shanker R, Large MJ, Smith RJ, Maspero R, Ogilvie SP, Scheerder J, Han J, Backes C, Razal JM, Florescu M, Keddie JL, Coleman JN, Dalton AB. Mechanochromic and Thermochromic Sensors Based on Graphene Infused Polymer Opals. Adv Funct Mater 2020; 30:2002473. [PMID: 32774202 PMCID: PMC7406018 DOI: 10.1002/adfm.202002473] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 05/05/2023]
Abstract
High quality opal-like photonic crystals containing graphene are fabricated using evaporation-driven self-assembly of soft polymer colloids. A miniscule amount of pristine graphene within a colloidal crystal lattice results in the formation of colloidal crystals with a strong angle-dependent structural color and a stop band that can be reversibly shifted across the visible spectrum. The crystals can be mechanically deformed or can reversibly change color as a function of their temperature, hence their sensitive mechanochromic and thermochromic response make them attractive candidates for a wide range of visual sensing applications. In particular, it is shown that the crystals are excellent candidates for visual strain sensors or integrated time-temperature indicators which act over large temperature windows. Given the versatility of these crystals, this method represents a simple, inexpensive, and scalable approach to produce multifunctional graphene infused synthetic opals and opens up exciting applications for novel solution-processable nanomaterial based photonics.
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Affiliation(s)
- Izabela Jurewicz
- Department of PhysicsFaculty of Engineering & Physical SciencesUniversity of SurreyGuildfordGU2 7XHUK
| | | | - Ravi Shanker
- Department of PhysicsFaculty of Engineering & Physical SciencesUniversity of SurreyGuildfordGU2 7XHUK
- Laboratory of Nano‐Optics and Organic ElectronicsDepartment of Science and TechnologyLinköping UniversityNorrköpingSE‐601 74Sweden
| | | | - Ronan J. Smith
- School of PhysicsCRANN and AMBERTrinity College DublinDublin 2Ireland
| | - Ross Maspero
- Department of PhysicsFaculty of Engineering & Physical SciencesUniversity of SurreyGuildfordGU2 7XHUK
- Advanced Technology InstituteUniversity of SurreyGuildfordGU2 7XHUK
| | | | | | - Jun Han
- Chinese Academy of SciencesCN‐36220 QuanzhouCN CN‐36220QuanzhChina
| | - Claudia Backes
- Applied Physical ChemistryUniversity of HeidelbergHeidelberg69120Germany
| | - Joselito M. Razal
- Institute for Frontier MaterialsDeakin UniversityGeelongVIC3216Australia
| | - Marian Florescu
- Department of PhysicsFaculty of Engineering & Physical SciencesUniversity of SurreyGuildfordGU2 7XHUK
- Advanced Technology InstituteUniversity of SurreyGuildfordGU2 7XHUK
| | - Joseph L. Keddie
- Department of PhysicsFaculty of Engineering & Physical SciencesUniversity of SurreyGuildfordGU2 7XHUK
| | | | - Alan B. Dalton
- Department of PhysicsUniversity of SussexBrightonBN1 9RHUK
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25
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Grieger S, Szydłowska BM, Rao VJ, Steinmann E, Dodds M, Gholamvand Z, Duesberg GS, Zaumseil J, Backes C. Site‐Selective Oxidation of Monolayered Liquid‐Exfoliated WS
2
by Shielding the Basal Plane through Adsorption of a Facial Amphiphile. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202005730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Sebastian Grieger
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Beata M. Szydłowska
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
- Institute of Physics, EIT 2 Faculty of Electrical Engineering and Information Technology Universität der Bundeswehr München Werner-Heisenberg-Weg 39 85577 Neubiberg Germany
| | - Vaishnavi J. Rao
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Eva Steinmann
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Marcus Dodds
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Zahra Gholamvand
- School of Physics and CRANN & AMBER Research Centres Trinity College Dublin Dublin 2 Ireland
| | - Georg S. Duesberg
- Institute of Physics, EIT 2 Faculty of Electrical Engineering and Information Technology Universität der Bundeswehr München Werner-Heisenberg-Weg 39 85577 Neubiberg Germany
| | - Jana Zaumseil
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
- Centre for Advanced Materials Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 225 69120 Heidelberg Germany
| | - Claudia Backes
- Institute for Physical Chemistry Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 253 69120 Heidelberg Germany
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26
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Chen X, Denninger P, Stimpel‐Lindner T, Spiecker E, Duesberg GS, Backes C, Knirsch KC, Hirsch A. Cover Feature: Defect Engineering of Two‐Dimensional Molybdenum Disulfide (Chem. Eur. J. 29/2020). Chemistry 2020. [DOI: 10.1002/chem.202001486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Xin Chen
- Department of Chemistry and PharmacyFriedrich-Alexander-Universität (FAU) Erlangen-Nürnberg Nikolaus-Fiebiger-Straße 10 91058 Erlangen Germany
| | - Peter Denninger
- Center for Nanoanalysis and Electron Microscopy (CENEM) &Institute of Micro- and Nanostructure Research (IMN)Interdisciplinary Center for Nanostructured Films (IZNF)Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg Cauerstraße 3 91058 Erlangen Germany
| | - Tanja Stimpel‐Lindner
- Institute of Physics, EIT 2, Faculty of Electrical Engineering and Information TechnologyUniversität der Bundeswehr 85579 Neubiberg Germany
| | - Erdmann Spiecker
- Center for Nanoanalysis and Electron Microscopy (CENEM) &Institute of Micro- and Nanostructure Research (IMN)Interdisciplinary Center for Nanostructured Films (IZNF)Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg Cauerstraße 3 91058 Erlangen Germany
| | - Georg S. Duesberg
- Institute of Physics, EIT 2, Faculty of Electrical Engineering and Information TechnologyUniversität der Bundeswehr 85579 Neubiberg Germany
| | - Claudia Backes
- Institute of Physical ChemistryHeidelberg University Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Kathrin C. Knirsch
- Department of Chemistry and PharmacyFriedrich-Alexander-Universität (FAU) Erlangen-Nürnberg Nikolaus-Fiebiger-Straße 10 91058 Erlangen Germany
| | - Andreas Hirsch
- Department of Chemistry and PharmacyFriedrich-Alexander-Universität (FAU) Erlangen-Nürnberg Nikolaus-Fiebiger-Straße 10 91058 Erlangen Germany
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27
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Chen X, Denninger P, Stimpel-Lindner T, Spiecker E, Duesberg GS, Backes C, Knirsch KC, Hirsch A. Defect Engineering of Two-Dimensional Molybdenum Disulfide. Chemistry 2020; 26:6535-6544. [PMID: 32141636 PMCID: PMC7317841 DOI: 10.1002/chem.202000286] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Indexed: 01/06/2023]
Abstract
Two‐dimensional (2D) molybdenum disulfide (MoS2) holds great promise in electronic and optoelectronic applications owing to its unique structure and intriguing properties. The intrinsic defects such as sulfur vacancies (SVs) of MoS2 nanosheets are found to be detrimental to the device efficiency. To mitigate this problem, functionalization of 2D MoS2 using thiols has emerged as one of the key strategies for engineering defects. Herein, we demonstrate an approach to controllably engineer the SVs of chemically exfoliated MoS2 nanosheets using a series of substituted thiophenols in solution. The degree of functionalization can be tuned by varying the electron‐withdrawing strength of substituents in thiophenols. We find that the intensity of 2LA(M) peak normalized to A1g peak strongly correlates to the degree of functionalization. Our results provide a spectroscopic indicator to monitor and quantify the defect engineering process. This method of MoS2 defect functionalization in solution also benefits the further exploration of defect‐free MoS2 for a wide range of applications.
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Affiliation(s)
- Xin Chen
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058, Erlangen, Germany
| | - Peter Denninger
- Center for Nanoanalysis and Electron Microscopy (CENEM) &, Institute of Micro- and Nanostructure Research (IMN), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Cauerstraße 3, 91058, Erlangen, Germany
| | - Tanja Stimpel-Lindner
- Institute of Physics, EIT 2, Faculty of Electrical Engineering and Information Technology, Universität der Bundeswehr, 85579, Neubiberg, Germany
| | - Erdmann Spiecker
- Center for Nanoanalysis and Electron Microscopy (CENEM) &, Institute of Micro- and Nanostructure Research (IMN), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Cauerstraße 3, 91058, Erlangen, Germany
| | - Georg S Duesberg
- Institute of Physics, EIT 2, Faculty of Electrical Engineering and Information Technology, Universität der Bundeswehr, 85579, Neubiberg, Germany
| | - Claudia Backes
- Institute of Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Kathrin C Knirsch
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058, Erlangen, Germany
| | - Andreas Hirsch
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058, Erlangen, Germany
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28
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Foschi F, Synnatschke K, Grieger S, Zhang W, Wadepohl H, Schröder RR, Backes C, Gade LH. Front Cover: Luminogens for Aggregation‐Induced Emission via Titanium‐Mediated Double Nucleophilic Addition to 2,5‐Dialkynylpyridines: Formation and Transformation of the Emitting Aggregates (Chem. Eur. J. 19/2020). Chemistry 2020. [DOI: 10.1002/chem.202000375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Francesco Foschi
- Institute of Inorganic Chemistry Heidelberg University Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Kevin Synnatschke
- Applied Physical Chemistry Heidelberg University Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Sebastian Grieger
- Applied Physical Chemistry Heidelberg University Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Wen‐Shan Zhang
- Centre for Advanced Materials Heidelberg University Im Neuenheimer Feld 225 69120 Heidelberg Germany
| | - Hubert Wadepohl
- Institute of Inorganic Chemistry Heidelberg University Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Rasmus R. Schröder
- Centre for Advanced Materials Heidelberg University Im Neuenheimer Feld 225 69120 Heidelberg Germany
| | - Claudia Backes
- Applied Physical Chemistry Heidelberg University Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Lutz H. Gade
- Institute of Inorganic Chemistry Heidelberg University Im Neuenheimer Feld 270 69120 Heidelberg Germany
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29
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Foschi F, Synnatschke K, Grieger S, Zhang WS, Wadepohl H, Schröder RR, Backes C, Gade LH. Luminogens for Aggregation-Induced Emission via Titanium-Mediated Double Nucleophilic Addition to 2,5-Dialkynylpyridines: Formation and Transformation of the Emitting Aggregates. Chemistry 2020; 26:4269-4280. [PMID: 31912577 PMCID: PMC7187342 DOI: 10.1002/chem.201905611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Indexed: 12/12/2022]
Abstract
New luminogens for aggregation‐induced emission (AIE), which are characterized by a branched cross‐conjugated 2,6‐bis(1,2,2‐triarylvinyl)pyridine motif, have been synthesized exploiting the one‐pot Ti‐mediated tetraarylation of 2,6‐bis(arylethynyl)pyridines. Thin layer solid‐state emitters were prepared by spin‐coating of the luminogens, while AIE‐colloidal dispersions were investigated in terms of optical density and scattering behaviour. This has given insight into particle size distributions, time evolution of the aggregation and the influence of different functionalization patterns on the luminescence of molecular aggregates. In particular, a combination of extinction spectroscopy and dynamic light scattering is being proposed as a powerful method for investigating the dynamic aggregation process in AIE‐type colloids.
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Affiliation(s)
- Francesco Foschi
- Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Kevin Synnatschke
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Sebastian Grieger
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Wen-Shan Zhang
- Centre for Advanced Materials, Heidelberg University, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Hubert Wadepohl
- Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Rasmus R Schröder
- Centre for Advanced Materials, Heidelberg University, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Claudia Backes
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Lutz H Gade
- Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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30
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Foschi F, Synnatschke K, Grieger S, Zhang WS, Wadepohl H, Schröder RR, Backes C, Gade LH. Luminogens for Aggregation-Induced Emission via Titanium-Mediated Double Nucleophilic Addition to 2,5-Dialkynylpyridines: Formation and Transformation of the Emitting Aggregates. Chemistry 2020; 26:4169. [PMID: 32237112 DOI: 10.1002/chem.202000376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Invited for the cover of this issue are Lutz H. Gade, Claudia Backes, and co-workers at Heidelberg University. The image depicts 2-(1,2,2-triarylvinyl)-pyridines, which are luminogens for aggregation-induced emission which "light up" upon irradiation. Read the full text of the article at 10.1002/chem.201905611.
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Affiliation(s)
- Francesco Foschi
- Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Kevin Synnatschke
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Sebastian Grieger
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Wen-Shan Zhang
- Centre for Advanced Materials, Heidelberg University, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Hubert Wadepohl
- Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Rasmus R Schröder
- Centre for Advanced Materials, Heidelberg University, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Claudia Backes
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Lutz H Gade
- Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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31
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Lange RZ, Synnatschke K, Qi H, Huber N, Hofer G, Liang B, Huck C, Pucci A, Kaiser U, Backes C, Schlüter AD. Enriching and Quantifying Porous Single Layer 2D Polymers by Exfoliation of Chemically Modified van der Waals Crystals. Angew Chem Int Ed Engl 2020; 59:5683-5695. [PMID: 31821673 PMCID: PMC7154524 DOI: 10.1002/anie.201912705] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 11/26/2019] [Indexed: 01/11/2023]
Abstract
2D polymer sheets with six positively charged pyrylium groups at each pore edge in a stacked single crystal can be transformed into a 2D polymer with six pyridines per pore by exposure to gaseous ammonia. This reaction furnishes still a crystalline material with tunable protonation degree at regular nano-sized pores promising as separation membrane. The exfoliation is compared for both 2D polymers with the latter being superior. Its liquid phase exfoliation yields nanosheet dispersions, which can be size-selected using centrifugation cascades. Monolayer contents of ≈30 % are achieved with ≈130 nm sized sheets in mg quantities, corresponding to tens of trillions of monolayers. Quantification of nanosheet sizes, layer number and mass shows that this exfoliation is comparable to graphite. Thus, we expect that recent advances in exfoliation of graphite or inorganic crystals (e.g. scale-up, printing etc.) can be directly applied to this 2D polymer as well as to covalent organic frameworks.
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Affiliation(s)
- Ralph Z. Lange
- Institute for PolymersETH ZürichVladimir-Prelog-Weg 58093ZürichSwitzerland
| | - Kevin Synnatschke
- Institute of Physical ChemistryHeidelberg UniversityIm Neuenheimer Feld 25369120HeidelbergGermany
| | - Haoyuan Qi
- Central Facility of Electron MicroscopyElectron Microscopy Group of Materials ScienceUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Niklas Huber
- Institute for PolymersETH ZürichVladimir-Prelog-Weg 58093ZürichSwitzerland
| | - Gregor Hofer
- Institute for PolymersETH ZürichVladimir-Prelog-Weg 58093ZürichSwitzerland
- X-ray Platform D-MATLDepartment of MaterialsETH ZürichVladimir-Prelog-Weg 58093ZürichSwitzerland
| | - Baokun Liang
- Central Facility of Electron MicroscopyElectron Microscopy Group of Materials ScienceUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Christian Huck
- Kirchhoff Institute of PhysicsHeidelberg UniversityIm Neuenheimer Feld 22769120HeidelbergGermany
| | - Annemarie Pucci
- Kirchhoff Institute of PhysicsHeidelberg UniversityIm Neuenheimer Feld 22769120HeidelbergGermany
| | - Ute Kaiser
- Central Facility of Electron MicroscopyElectron Microscopy Group of Materials ScienceUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Claudia Backes
- Institute of Physical ChemistryHeidelberg UniversityIm Neuenheimer Feld 25369120HeidelbergGermany
| | - A. Dieter Schlüter
- Institute for PolymersETH ZürichVladimir-Prelog-Weg 58093ZürichSwitzerland
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32
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Lange RZ, Synnatschke K, Qi H, Huber N, Hofer G, Liang B, Huck C, Pucci A, Kaiser U, Backes C, Schlüter AD. Enriching and Quantifying Porous Single Layer 2D Polymers by Exfoliation of Chemically Modified van der Waals Crystals. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201912705] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ralph Z. Lange
- Institute for Polymers ETH Zürich Vladimir-Prelog-Weg 5 8093 Zürich Switzerland
| | - Kevin Synnatschke
- Institute of Physical Chemistry Heidelberg University Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Haoyuan Qi
- Central Facility of Electron Microscopy Electron Microscopy Group of Materials Science Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Niklas Huber
- Institute for Polymers ETH Zürich Vladimir-Prelog-Weg 5 8093 Zürich Switzerland
| | - Gregor Hofer
- Institute for Polymers ETH Zürich Vladimir-Prelog-Weg 5 8093 Zürich Switzerland
- X-ray Platform D-MATL Department of Materials ETH Zürich Vladimir-Prelog-Weg 5 8093 Zürich Switzerland
| | - Baokun Liang
- Central Facility of Electron Microscopy Electron Microscopy Group of Materials Science Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Christian Huck
- Kirchhoff Institute of Physics Heidelberg University Im Neuenheimer Feld 227 69120 Heidelberg Germany
| | - Annemarie Pucci
- Kirchhoff Institute of Physics Heidelberg University Im Neuenheimer Feld 227 69120 Heidelberg Germany
| | - Ute Kaiser
- Central Facility of Electron Microscopy Electron Microscopy Group of Materials Science Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Claudia Backes
- Institute of Physical Chemistry Heidelberg University Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - A. Dieter Schlüter
- Institute for Polymers ETH Zürich Vladimir-Prelog-Weg 5 8093 Zürich Switzerland
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33
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Backes C, Religi A, Moccozet L, Behar-Cohen F, Vuilleumier L, Bulliard JL, Vernez D. Sun exposure to the eyes: predicted UV protection effectiveness of various sunglasses. J Expo Sci Environ Epidemiol 2019; 29:753-764. [PMID: 30382242 PMCID: PMC6803516 DOI: 10.1038/s41370-018-0087-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 09/24/2018] [Accepted: 09/26/2018] [Indexed: 06/08/2023]
Abstract
The aim of this study was to assess solar ultraviolet radiation (UVR) doses received by the eyes in different exposure situations, and to predict the sun protection effectiveness provided by various styles of sunglasses at facial, periorbital, and ocular skin zones including the cornea and accounting for different head positions. A 3D numeric model was optimized to predict direct, diffuse and reflected erythemally weighted UVR doses received at various skin zones. Precisely defined facial, periorbital, and ocular skin zones, sunglasses (goggles, medium-, and large-sized sunglasses) and three head positions were modeled to simulate daily (08:00-17:00) and midday (12:00-14:00) UVR doses. The shading from sunglasses' frame and lenses' UVR transmission were used to calculate a predictive protection factor (PPF [%]). Highest ocular daily UVR doses were estimated at the uncovered cornea (1718.4 J/m2). Least sun protection was provided by middle-sized sunglasses with highest midday dose at the white lateral (290.8 J/m2) and lateral periorbital zones (390.9 J/m2). Goggles reached almost 100% protection at all skin zones. Large-sized sunglasses were highly effective in winter; however, their effectiveness depended on diffuse UVR doses received. In "looking-up" head positions highest midday UVR doses were received at the unprotected cornea (908.1 J/m2), totally protected when large-sized sunglasses are used. All tested sunglass lenses fully blocked UVR. Sunglasses' protection effectiveness is strongly influenced by geometry, wearing position, head positions, and exposure conditions. Sunglasses do not totally block UVR and should be combined with additional protection means. 3D modeling allows estimating UVR exposure of highly sensitive small skin zones, chronically exposed and rarely assessed.
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Affiliation(s)
- C Backes
- Institute for Work and Health, University of Lausanne and Geneva, 1010, Lausanne, Switzerland.
- Division of Chronic Diseases, University Institute of Social and Preventive Medicine, Lausanne University Hospital (CHUV), Lausanne, Switzerland.
| | - A Religi
- Centre Universitaire d'Informatique, University of Geneva, Geneva, Switzerland
| | - L Moccozet
- Centre Universitaire d'Informatique, University of Geneva, Geneva, Switzerland
| | - F Behar-Cohen
- INSERM U1138, Centre de Recherche des Cordeliers, Université Paris Descartes, Université Pierre et Marie Curie, Paris, France
| | - L Vuilleumier
- Federal Office of Meteorology and Climatology (MeteoSwiss), Payerne, Switzerland
| | - J L Bulliard
- Division of Chronic Diseases, University Institute of Social and Preventive Medicine, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - D Vernez
- Institute for Work and Health, University of Lausanne and Geneva, 1010, Lausanne, Switzerland
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34
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Religi A, Backes C, Chatelan A, Bulliard JL, Vuilleumier L, Moccozet L, Bochud M, Vernez D. Estimation of exposure durations for vitamin D production and sunburn risk in Switzerland. J Expo Sci Environ Epidemiol 2019; 29:742-752. [PMID: 30992519 DOI: 10.1038/s41370-019-0137-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 02/25/2019] [Accepted: 03/08/2019] [Indexed: 06/09/2023]
Abstract
Although overexposure to solar ultraviolet radiation (UVR) is responsible for cutaneous melanoma and epithelial skin cancer and can cause negative health effects such as sunburn, a "little and often" exposure regime is often suggested to produce naturally recommended vitamin D levels, being essential for skeletal health. This study aimed to quantify solar UV doses needed to trigger 1000 International Units (IU) vitamin D doses and, at the same time, producing sunburn in Switzerland. Solar UV erythema irradiance (in mW/m2) measured at four meteorological stations in Switzerland for the period 2005-2017 were used to evaluate effective solar UV radiation producing 1000 IU vitamin D doses in skin phototype II and III individuals. Daily solar UV exposure durations (in minutes) needed to produce vitamin D with limited sunburn risk were estimated while considering mean vitamin D food intake of the Swiss population and seasonal skin coverage. In summer and spring, with 22% of uncovered skin, 1000 IU vitamin D doses are synthesized in 10-15 min of sun exposure for adults. Exposure durations between erythema risk and 1000 IU vitamin D production vary between 9 and 46 min. In winter and autumn, the recommended vitamin D production without sunburn risks often unachievable, since up to 6.5 h of sun exposure might be necessary considering 8-10% of uncovered skin surface. The vitamin D food intake only represented 10% of the recommended vitamin D production and remained unchanged throughout the year. These findings might clarify why vitamin D deficiency is common in Switzerland. Moreover, exposure durations between recommended vitamin D and increased sunburn risk might only differ by few minutes. Without additional oral vitamin D supplementation, daily doses of vitamin D (1000 IU) are not reachable in autumn and winter months in Switzerland.
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Affiliation(s)
- A Religi
- Centre Universitaire d'Informatique (CUI), University of Geneva, Geneva, Switzerland.
| | - C Backes
- Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital (CHUV), 1010, Lausanne, Switzerland
- Institute for Work and Health, University of Lausanne and Geneva, 1010 Epalignes- Lausanne, Lausanne, Switzerland
| | - A Chatelan
- Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital (CHUV), 1010, Lausanne, Switzerland
| | - J-L Bulliard
- Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital (CHUV), 1010, Lausanne, Switzerland
| | - L Vuilleumier
- Federal Office of Meteorology and Climatology (MeteoSwiss), Payerne, Switzerland
| | - L Moccozet
- Centre Universitaire d'Informatique (CUI), University of Geneva, Geneva, Switzerland
| | - M Bochud
- Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital (CHUV), 1010, Lausanne, Switzerland
| | - D Vernez
- Institute for Work and Health, University of Lausanne and Geneva, 1010 Epalignes- Lausanne, Lausanne, Switzerland
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35
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Religi A, Backes C, Chatelan A, Bulliard JL, Vuilleumier L, Moccozet L, Bochud M, Vernez D. Correction to: Estimation of exposure durations for vitamin D production and sunburn risk in Switzerland. J Expo Sci Environ Epidemiol 2019; 29:862. [PMID: 31065038 DOI: 10.1038/s41370-019-0143-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In the original article, the authorship list was given as "A. Religi1, C. Backes2,3, A. Chatelan2, J.-L. Bulliard2, L. Vuilleumier4, L. Moccozet1, M. Bochud2, D. Vernez3". This has been updated to "A. Religi*1, C. Backes*2,3, A. Chatelan2, J.-L. Bulliard2, L. Vuilleumier4, L. Moccozet1, M. Bochud 2, D. Vernez3".
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Affiliation(s)
- A Religi
- Centre Universitaire d'Informatique (CUI), University of Geneva, Geneva, Switzerland.
| | - C Backes
- Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital (CHUV), 1010, Lausanne, Switzerland
- Institute for Work and Health, University of Lausanne and Geneva, 1010 Epalignes- Lausanne, Lausanne, Switzerland
| | - A Chatelan
- Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital (CHUV), 1010, Lausanne, Switzerland
| | - J-L Bulliard
- Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital (CHUV), 1010, Lausanne, Switzerland
| | - L Vuilleumier
- Federal Office of Meteorology and Climatology (MeteoSwiss), Payerne, Switzerland
| | - L Moccozet
- Centre Universitaire d'Informatique (CUI), University of Geneva, Geneva, Switzerland
| | - M Bochud
- Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital (CHUV), 1010, Lausanne, Switzerland
| | - D Vernez
- Institute for Work and Health, University of Lausanne and Geneva, 1010 Epalignes- Lausanne, Lausanne, Switzerland
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36
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Backes C. Ten Years of Liquid-phase Exfoliation of Layered Crystals – A Bright Future ahead? Chimia (Aarau) 2019. [DOI: 10.2533/chimia.2019.498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Layered materials are an abundant source of new nanostructures when thinned down to display fascinating layer number-dependent properties due to quantum confinement in two dimensions. About ten years ago, it was first demonstrated that layered crystals can be exfoliated down to monolayers
in the liquid phase by a relatively simple and scalable methodology termed liquid-phase exfoliation that is widely applicable to many structures. By now, >10 classes of layered materials have been made accessible as two-dimensional nanosheets by this technique. In this article, advancements
in exfoliation, size selection and characterisation are summarised. Remaining challenges, open questions and perspectives are also discussed.
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37
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Rodrigues L, Teodoro A, Santos A, Backes C, Rocha J, Giongo P, Dos Santos Y. Integração Lavoura-Pecuária-Floresta: Interação entre Componentes e Sustentabilidade do Sistema. ARCH ZOOTEC 2019. [DOI: 10.21071/az.v68i263.4207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
O impacto ambiental provocado por práticas agropecuárias extrativistas é preocupante a nível mundial do ponto de vista ambiental e econômico, visto que a degradação das áreas causa impacto ambiental, afeta diretamente a produção vegetal e indiretamente a produção animal. Com a finalidade de diminuir os danos ao meio ambiente e adotar modelos de produção mais eficientes e sustentáveis, o governo brasileiro lançou políticas governamentais com incentivo por meio de financiamento para implantação destes. A iLPF consiste no cultivo simultâneo ou em sucessão para produção de alimento de origem animal e vegetal além da produção de recursos madeireiros e não-madeireiros. Esse sistema possibilita a diversificação da renda, maior produtividade, benefícios ao solo e ao sistema, recuperação de áreas degradadas e é de baixo impacto ambiental, contudo esses podem não ocorrer em circunstâncias de implantação e manejo incorreto de seus componentes resultando em um cenário de desequilíbrio e competição. O componente florestal, por permanecer por mais tempo na área de produção, deve-se dar atenção à escolha da espécie a ser utilizada bem como ao arranjo a ser adotado, visto que pode influenciar seu próprio desenvolvimento e dos demais componentes vegetais. Frente a complexidade do sistema e seus potenciais benefícios, são essenciais pesquisas acerca da iLPF para síntese de informações sobre os melhores modelos a serem adotados em função da diversidade ambiental e realidades socioeconômicas brasileiras.
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38
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Backes C, Campi D, Szydlowska BM, Synnatschke K, Ojala E, Rashvand F, Harvey A, Griffin A, Sofer Z, Marzari N, Coleman JN, O'Regan DD. Equipartition of Energy Defines the Size-Thickness Relationship in Liquid-Exfoliated Nanosheets. ACS Nano 2019; 13:7050-7061. [PMID: 31199123 DOI: 10.1021/acsnano.9b02234] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Liquid phase exfoliation is a commonly used method to produce 2D nanosheets from a range of layered crystals. However, such nanosheets display broad size and thickness distributions and correlations between area and thickness, issues that limit nanosheet application potential. To understand the factors controlling the exfoliation process, we have liquid-exfoliated 11 different layered materials, size-selecting each into fractions before using AFM to measure the nanosheet length, width, and thickness distributions for each fraction. The resultant data show a clear power-law scaling of nanosheet area with thickness for each material. We have developed a simple nonequilibrium thermodynamics-based model predicting that the power-law prefactor is proportional to both the ratios of in-plane-tearing/out-of-plane-peeling energies and in-plane/out-of-plane moduli. By comparing the experimental data with the modulus ratio calculated from first-principles, we find close agreement between experiment and theory. This supports our hypothesis that energy equipartition holds between nanosheet tearing and peeling during sonication-assisted exfoliation.
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Affiliation(s)
- Claudia Backes
- Chair of Applied Physical Chemistry , University of Heidelberg , Im Neuenheimer Feld 253 , 69120 Heidelberg , Germany
| | - Davide Campi
- Theory and Simulation of Materials (THEOS) and National Centre for Computational Design and Discovery of Novel Materials (MARVEL) , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Beata M Szydlowska
- Chair of Applied Physical Chemistry , University of Heidelberg , Im Neuenheimer Feld 253 , 69120 Heidelberg , Germany
- School of Physics and CRANN & AMBER Research Centers , Trinity College Dublin, The University of Dublin , Dublin 2 , Ireland
| | - Kevin Synnatschke
- Chair of Applied Physical Chemistry , University of Heidelberg , Im Neuenheimer Feld 253 , 69120 Heidelberg , Germany
| | - Ezgi Ojala
- Chair of Applied Physical Chemistry , University of Heidelberg , Im Neuenheimer Feld 253 , 69120 Heidelberg , Germany
| | - Farnia Rashvand
- Chair of Applied Physical Chemistry , University of Heidelberg , Im Neuenheimer Feld 253 , 69120 Heidelberg , Germany
| | - Andrew Harvey
- School of Physics and CRANN & AMBER Research Centers , Trinity College Dublin, The University of Dublin , Dublin 2 , Ireland
| | - Aideen Griffin
- School of Physics and CRANN & AMBER Research Centers , Trinity College Dublin, The University of Dublin , Dublin 2 , Ireland
| | - Zdenek Sofer
- Department of Inorganic Chemistry , University of Chemistry and Technology Prague , Technická 5 , 166 28 Prague 6 , Czech Republic
| | - Nicola Marzari
- Theory and Simulation of Materials (THEOS) and National Centre for Computational Design and Discovery of Novel Materials (MARVEL) , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland
| | - Jonathan N Coleman
- School of Physics and CRANN & AMBER Research Centers , Trinity College Dublin, The University of Dublin , Dublin 2 , Ireland
| | - David D O'Regan
- School of Physics and CRANN & AMBER Research Centers , Trinity College Dublin, The University of Dublin , Dublin 2 , Ireland
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Vega-Mayoral V, Tian R, Kelly AG, Griffin A, Harvey A, Borrelli M, Nisi K, Backes C, Coleman JN. Solvent exfoliation stabilizes TiS 2 nanosheets against oxidation, facilitating lithium storage applications. Nanoscale 2019; 11:6206-6216. [PMID: 30874697 DOI: 10.1039/c8nr09446b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Titanium disulfide is a promising material for a range of applications, including lithium-ion battery (LIB) anodes. However, its application potential has been severely hindered by the tendency of exfoliated TiS2 to rapidly oxidize under ambient conditions. Herein, we confirm that, although layered TiS2 powder can be exfoliated by sonication in aqueous surfactant solutions, the resultant nanosheets oxidise almost completely within hours. However, we find that upon performing the exfoliation in the solvent cyclohexyl-pyrrolidone (CHP), the oxidation is almost completely suppressed. TiS2 nanosheets dispersed in CHP and stored at 4 °C in an open atmosphere for 90 days remained up to 95% intact. In addition, CHP-exfoliated nanosheets did not show any evidence of oxidation for at least 30 days after being transformed into dry films even when stored under ambient conditions. This stability, probably a result of a residual CHP coating, allows TiS2 nanosheets to be deployed in applications. To demonstrate this, we prepared lithium ion battery anodes from nano : nano composites of TiS2 nanosheets mixed with carbon nanotubes. These anodes displayed reversible capacities (920 mA h g-1) close to the theoretical value and showed good rate performance and cycling capability.
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40
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Djamil J, Hansen AL, Backes C, Bensch W, Schürmann U, Kienle L, Düvel A, Heitjans P. Using light, X-rays and electrons for evaluation of the nanostructure of layered materials. Nanoscale 2018; 10:21142-21150. [PMID: 30406795 DOI: 10.1039/c8nr07287f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
As a case study for the evaluation of the nanostructure of layered materials, we report on results of the comprehensive characterization of high-energy ball-milled layered molybdenum disulfide (2H-MoS2) on different length scales. Analysis of X-ray powder diffraction patterns (XRPDs) including the Debye background at low scattering angles caused by uncorrelated single or few-layer MoS2 slabs (full scattering model), yield much more precise data about the average stacking degree than routine XRPD evaluation, and an estimation of the amount of single layer material is possible. Reflections with super Lorentzian line shape can be satisfactorily modeled assuming different stacking sequences induced by the mechanical forces exerted during the high-energy ball-mill process. An advanced analysis of UV-Vis spectra to determine layer number and lateral crystallite size, which was recently developed for liquid exfoliation materials, is used for the first time, and the results demonstrate the universal applicability of the approach. The data obtained with this analysis support the main findings of evaluation of the XRPD data. Both methods clearly evidence that increasing the duration of high-energy ball-mill treatment leads to an increase of material with decreasing average stacking and a reduction of the lateral size of the slabs. Finally, high-resolution transmission electron microscopy enabled identification of defects which can hardly be detected in XRPDs or in UV-Vis spectra.
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Affiliation(s)
- John Djamil
- Institute of Inorganic Chemistry, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Str. 2, 24118 Kiel, Germany.
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41
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Harvey A, Backes C, Boland JB, He X, Griffin A, Szydlowska B, Gabbett C, Donegan JF, Coleman JN. Non-resonant light scattering in dispersions of 2D nanosheets. Nat Commun 2018; 9:4553. [PMID: 30385771 PMCID: PMC6212482 DOI: 10.1038/s41467-018-07005-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/05/2018] [Indexed: 11/25/2022] Open
Abstract
Extinction spectra of nanomaterial suspensions can be dominated by light scattering, hampering quantitative spectral analysis. No simple models exist for the wavelength-dependence of the scattering coefficients in suspensions of arbitrary-sized, high-aspect-ratio nanoparticles. Here, suspensions of BN, talc, GaS, Ni(OH)2, Mg(OH)2 and Cu(OH)2 nanosheets are used to explore non-resonant scattering in wide-bandgap 2D nanomaterials. Using an integrating sphere, scattering coefficient (σ) spectra were measured for a number of size-selected fractions for each nanosheet type. Generally, σ scales as a power-law with wavelength in the non-resonant regime: σ(λ)∝[λ/〈L〉]−m, where 〈L〉 is the mean nanosheet length. For all materials, the scattering exponent, m, forms a master-curve, transitioning from m = 4 to m = 2, as the characteristic nanosheet area increases, indicating a transition from Rayleigh to van der Hulst scattering. In addition, once material density and refractive index are factored out, the proportionality constant relating σ to [λ/〈L〉]−m, also forms a master-curve when plotted versus 〈L〉. Quantitative analysis of the extinction spectra of dispersions of 2D materials is complicated by light scattering. Here, the authors investigate non-resonant scattering in suspensions of wide-bandgap nanosheets, and develop a general model which allows the scattering spectra to be used as metrics for particle size in nanosheet dispersions.
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Affiliation(s)
- Andrew Harvey
- CRANN & AMBER Research Centers, Trinity College Dublin, Dublin 2, Ireland.,School of Physics, Trinity College Dublin, Dublin 2, Ireland
| | - Claudia Backes
- Chair of Applied Physical Chemistry, University of Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - John B Boland
- CRANN & AMBER Research Centers, Trinity College Dublin, Dublin 2, Ireland.,School of Physics, Trinity College Dublin, Dublin 2, Ireland
| | - Xiaoyun He
- CRANN & AMBER Research Centers, Trinity College Dublin, Dublin 2, Ireland.,School of Physics, Trinity College Dublin, Dublin 2, Ireland
| | - Aideen Griffin
- CRANN & AMBER Research Centers, Trinity College Dublin, Dublin 2, Ireland.,School of Physics, Trinity College Dublin, Dublin 2, Ireland
| | - Beata Szydlowska
- CRANN & AMBER Research Centers, Trinity College Dublin, Dublin 2, Ireland.,School of Physics, Trinity College Dublin, Dublin 2, Ireland
| | - Cian Gabbett
- CRANN & AMBER Research Centers, Trinity College Dublin, Dublin 2, Ireland.,School of Physics, Trinity College Dublin, Dublin 2, Ireland
| | - John F Donegan
- CRANN & AMBER Research Centers, Trinity College Dublin, Dublin 2, Ireland.,School of Physics, Trinity College Dublin, Dublin 2, Ireland
| | - Jonathan N Coleman
- CRANN & AMBER Research Centers, Trinity College Dublin, Dublin 2, Ireland. .,School of Physics, Trinity College Dublin, Dublin 2, Ireland.
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42
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Bertolazzi S, Gobbi M, Zhao Y, Backes C, Samorì P. Molecular chemistry approaches for tuning the properties of two-dimensional transition metal dichalcogenides. Chem Soc Rev 2018; 47:6845-6888. [PMID: 30043037 DOI: 10.1039/c8cs00169c] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Two-dimensional (2D) semiconductors, such as ultrathin layers of transition metal dichalcogenides (TMDs), offer a unique combination of electronic, optical and mechanical properties, and hold potential to enable a host of new device applications spanning from flexible/wearable (opto)electronics to energy-harvesting and sensing technologies. A critical requirement for developing practical and reliable electronic devices based on semiconducting TMDs consists in achieving a full control over their charge-carrier polarity and doping. Inconveniently, such a challenging task cannot be accomplished by means of well-established doping techniques (e.g. ion implantation and diffusion), which unavoidably damage the 2D crystals resulting in degraded device performances. Nowadays, a number of alternatives are being investigated, including various (supra)molecular chemistry approaches relying on the combination of 2D semiconductors with electroactive donor/acceptor molecules. As yet, a large variety of molecular systems have been utilized for functionalizing 2D TMDs via both covalent and non-covalent interactions. Such research endeavours enabled not only the tuning of the charge-carrier doping but also the engineering of the optical, electronic, magnetic, thermal and sensing properties of semiconducting TMDs for specific device applications. Here, we will review the most enlightening recent advancements in experimental (supra)molecular chemistry methods for tailoring the properties of atomically-thin TMDs - in the form of substrate-supported or solution-dispersed nanosheets - and we will discuss the opportunities and the challenges towards the realization of novel hybrid materials and devices based on 2D semiconductors and molecular systems.
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Affiliation(s)
- Simone Bertolazzi
- Université de Strasbourg, CNRS, ISIS, 8 alleé Gaspard Monge, 67000 Strasbourg, France.
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43
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Kłopotowski Ł, Czechowski N, Mitioglu AA, Backes C, Maude DK, Plochocka P. Long-lived photoluminescence polarization of localized excitons in liquid exfoliated monolayer enriched WS 2. Nanotechnology 2018; 29:335703. [PMID: 29790860 DOI: 10.1088/1361-6528/aac73e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Monolayer transition metal dichalcogenides (TMDs) constitute a family of materials, in which coupled spin-valley physics can be explored and which could find applications in novel optoelectronic devices. However, before applications can be designed, a scalable method of monolayer extraction is required. Liquid phase exfoliation is a technique providing large quantities of the monolayer material, but the spin-valley properties of thus obtained TMDs are unknown. In this work, we employ steady-state and time-resolved photoluminescence (PL) to investigate the relaxation dynamics of localized excitons (LXs) in liquid exfoliated WS2. The results reveal that the circular polarization lifetime of the PL exceeds by at least an order of magnitude the PL lifetime. A rate equations model allows us to reproduce quantitatively the experimental data and to conclude that the observed large and long-lived PL polarization originates from efficient trapping of free excitons at localization sites hindering the intervalley relaxation. Furthermore, our results show that the depolarization process is inefficient for LXs. We discuss various mechanisms leading to this effect such as suppression of intervalley scattering of the LXs or inefficient spin relaxation of the holes.
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Affiliation(s)
- Ł Kłopotowski
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
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44
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Kelly AG, Hallam T, Backes C, Harvey A, Esmaeily AS, Godwin I, Coelho J, Nicolosi V, Lauth J, Kulkarni A, Kinge S, Siebbeles LDA, Duesberg GS, Coleman JN. All-printed thin-film transistors from networks of liquid-exfoliated nanosheets. Science 2017; 356:69-73. [DOI: 10.1126/science.aal4062] [Citation(s) in RCA: 305] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 03/13/2017] [Indexed: 01/18/2023]
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45
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Backes C, Hanlon D, Szydlowska BM, Harvey A, Smith RJ, Higgins TM, Coleman JN. Preparation of Liquid-exfoliated Transition Metal Dichalcogenide Nanosheets with Controlled Size and Thickness: A State of the Art Protocol. J Vis Exp 2016:54806. [PMID: 28060312 PMCID: PMC5226436 DOI: 10.3791/54806] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
We summarize recent advances in the production of liquid-exfoliated transition metal dichalcogenide (TMD) nanosheets with controlled size and thickness. Layered crystals of molybdenum disulphide (MoS2) and tungsten disulphide (WS2) are exfoliated in aqueous surfactant solution by sonication. This yields highly polydisperse mixtures containing nanosheets with broad size and thickness distributions. However, for most purposes, specific sizes (in terms of both lateral dimension and thickness) are required. For example, large and thin nanosheets are desired for (opto) electronic applications, while laterally small nanosheets are interesting for catalytic applications. Therefore, post-exfoliation size selection is an important step that we address here. We provide a detailed protocol on the efficient size selection in large quantities by liquid cascade centrifugation and the size and thickness quantification by statistical microscopic analysis (atomic force microscopy and transmission electron microscopy). The comparison of MoS2 and WS2 shows that both materials are size-selected in a similar way by the same procedure. Importantly, the dispersions of size-selected nanosheets show systematic changes in their optical extinction spectra with size due to edge and confinement effects. We show how these optical changes are related quantitatively to the nanosheets dimensions and describe how mean nanosheets length and layer number can be extracted reliably from the extinction spectra. The exfoliation and size selection protocol can be applied to a broad range of layered crystals as we have previously demonstrated for graphene, gallium sulphide (GaS) and black phosphorus.
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Affiliation(s)
- Claudia Backes
- Chair of Applied Physical Chemistry, Ruprecht-Karls University Heidelberg;
| | | | | | | | | | - Thomas M Higgins
- Chair of Applied Physical Chemistry, Ruprecht-Karls University Heidelberg
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46
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Boland CS, Khan U, Ryan G, Barwich S, Charifou R, Harvey A, Backes C, Li Z, Ferreira MS, Mobius ME, Young RJ, Coleman JN. Sensitive electromechanical sensors using viscoelastic graphene-polymer nanocomposites. Science 2016; 354:1257-1260. [DOI: 10.1126/science.aag2879] [Citation(s) in RCA: 546] [Impact Index Per Article: 68.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 11/11/2016] [Indexed: 01/20/2023]
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47
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Kłopotowski Ł, Backes C, Mitioglu AA, Vega-Mayoral V, Hanlon D, Coleman JN, Ivanov VY, Maude DK, Plochocka P. Revealing the nature of excitons in liquid exfoliated monolayer tungsten disulphide. Nanotechnology 2016; 27:425701. [PMID: 27606691 DOI: 10.1088/0957-4484/27/42/425701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Transition metal dichalcogenides (TMD) hold promise for applications in novel optoelectronic devices. There is therefore a need for materials that can be obtained in large quantities and with well understood optical properties. In this report, we present thorough photoluminescence (PL) investigations of monolayer tungsten disulphide obtained via liquid phase exfoliation. As shown by microscopy studies, the exfoliated nanosheets have dimensions of tens of nanometers and thickness of 2.5 monolayers on average. The monolayer content is about 20%. Our studies show that at low temperature the PL is dominated by excitons localized on nanosheet edges. As a consequence, the PL is strongly sensitive to the environment and exhibits an enhanced splitting in magnetic field. As the temperature is increased, the excitons are thermally excited out of the defect states and the dominant transition is that of the negatively charged exciton. Furthermore, upon excitation with a circularly polarized light, the PL retains a degree of polarization reaching 50% and inherited from the valley polarized photoexcited excitons. The studies of PL dynamics reveal that the PL lifetime is on the order of 10 ps, which is probably limited by non-radiative processes. Our results underline the potential of liquid exfoliated TMD monolayers in large scale optoelectronic devices.
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Affiliation(s)
- Ł Kłopotowski
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikw 32/46, 02-668 Warsaw, Poland
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48
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Buckinx F, Paquot N, Allepaerts S, Reginster JY, Petermans J, Backes C, Bruyère O. Teneur en énergie et en nutriments des repas servis et consommés par les sujets âgés résidant en maison de repos. NUTR CLIN METAB 2016. [DOI: 10.1016/j.nupar.2016.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
The possibility to produce and process graphene, related 2D crystals, and heterostructures in the liquid phase makes them promising materials for an ever-growing class of applications as composite materials, sensors, in flexible optoelectronics, and energy storage and conversion. In particular, the ability to formulate functional inks with on-demand rheological and morphological properties, i.e., lateral size and thickness of the dispersed 2D crystals, is a step forward toward the development of industrial-scale, reliable, inexpensive printing/coating processes, a boost for the full exploitation of such nanomaterials. Here, the exfoliation strategies of graphite and other layered crystals are reviewed, along with the advances in the sorting of lateral size and thickness of the exfoliated sheets together with the formulation of functional inks and the current development of printing/coating processes of interest for the realization of 2D-crystal-based devices.
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Affiliation(s)
- Francesco Bonaccorso
- Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, Genova, 16163, Italy
| | - Antonino Bartolotta
- CNR-IPCF, Istituto per i Processi Chimico-Fisici, Via F. Stagno D'Alcontres 37, Messina, 98158, Italy
| | - Jonathan N Coleman
- School of Physics and CRANN, Trinity College Dublin, Pearse St, Dublin 2, Ireland
| | - Claudia Backes
- Applied Physical Chemistry, University of Heidelberg, Im Neuenheimer Feld 253, Heidelberg, 69120, Germany
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50
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Seral-Ascaso A, Metel S, Pokle A, Backes C, Zhang CJ, Nerl HC, Rode K, Berner NC, Downing C, McEvoy N, Muñoz E, Harvey A, Gholamvand Z, Duesberg GS, Coleman JN, Nicolosi V. Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes. Nanoscale 2016; 8:11698-11706. [PMID: 27221399 DOI: 10.1039/c6nr01663d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization.
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Affiliation(s)
- A Seral-Ascaso
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - S Metel
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - A Pokle
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - C Backes
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - C J Zhang
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - H C Nerl
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - K Rode
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - N C Berner
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - C Downing
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland.
| | - N McEvoy
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - E Muñoz
- Instituto de Carboquímica ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain
| | - A Harvey
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Z Gholamvand
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - G S Duesberg
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - J N Coleman
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - V Nicolosi
- CRANN & AMBER, Trinity College Dublin, Pearse Street, Dublin 2, Ireland. and School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland and School of Chemistry, Trinity College Dublin, College Green, Dublin 2, Ireland
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