1
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Coke K, Johnson MJ, Robinson JB, Rettie AJE, Miller TS, Shearing PR. Illuminating Polysulfide Distribution in Lithium Sulfur Batteries; Tracking Polysulfide Shuttle Using Operando Optical Fluorescence Microscopy. ACS Appl Mater Interfaces 2024; 16. [PMID: 38598420 PMCID: PMC11056927 DOI: 10.1021/acsami.3c14612] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 03/01/2024] [Accepted: 03/08/2024] [Indexed: 04/12/2024]
Abstract
High-energy-density lithium sulfur (Li-S) batteries suffer heavily from the polysulfide shuttle effect, a result of the dissolution and transport of intermediate polysulfides from the cathode, into the electrolyte, and onto the anode, leading to rapid cell degradation. If this primary mechanism of cell failure is to be overcome, the distribution, dynamics, and degree of polysulfide transport must first be understood in depth. In this work, operando optical fluorescence microscope imaging of optically accessible Li-S cells is shown to enable real-time qualitative visualization of the spatial distribution of lithium polysulfides, both within the electrolyte and porous cathode. Quantitative determinations of spatial concentration are also possible at a low enough concentration. The distribution throughout cycling is monitored, including direct observation of polysulfide shuttling to the anode and consequent dendrite formation. This was enabled through the optimization of a selective fluorescent dye, verified to fluoresce proportionally with concentration of polysulfides within Li-S cells. This ability to directly and conveniently track the spatial distribution of soluble polysulfide intermediates in Li-S battery electrolytes, while the cell operates, has the potential to have a widespread impact across the field, for example, by enabling the influence of a variety of polysulfide mitigation strategies to be assessed and optimized, including in this work the LiNO3 additive.
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Affiliation(s)
- Kofi Coke
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, U.K.
| | - Michael J. Johnson
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, U.K.
| | - James B. Robinson
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot OX11 ORA, U.K.
- Advanced
Propulsion Lab, UCL East, University College
London, London E15 2JE, U.K.
| | - Alexander J. E. Rettie
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot OX11 ORA, U.K.
- Advanced
Propulsion Lab, UCL East, University College
London, London E15 2JE, U.K.
| | - Thomas S. Miller
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot OX11 ORA, U.K.
| | - Paul R. Shearing
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot OX11 ORA, U.K.
- Department
of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, U.K.
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2
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Zhang Z, Said S, Lovett AJ, Jervis R, Shearing PR, Brett DJL, Miller TS. The Influence of Cathode Degradation Products on the Anode Interface in Lithium-Ion Batteries. ACS Nano 2024; 18:9389-9402. [PMID: 38507591 PMCID: PMC10993644 DOI: 10.1021/acsnano.3c10208] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 03/07/2024] [Accepted: 03/13/2024] [Indexed: 03/22/2024]
Abstract
Degradation of cathode materials in lithium-ion batteries results in the presence of transition metal ions in the electrolyte, and these ions are known to play a major role in capacity fade and cell failure. Yet, while it is known that transition metal ions migrate from the metal oxide cathode and deposit on the graphite anode, their specific influence on anode reactions and structures, such as the solid electrolyte interphase (SEI), is still quite poorly understood due to the complexity in studying this interface in operational cells. In this work we combine operando electrochemical atomic force microscopy (EC-AFM), electrochemical quartz crystal microbalance (EQCM), and electrochemical impedance spectroscopy (EIS) measurements to probe the influence of a range of transition metal ions on the morphological, mechanical, chemical, and electrical properties of the SEI. By adding representative concentrations of Ni2+, Mn2+, and Co2+ ions into a commercially relevant battery electrolyte, the impacts of each on the formation and stability of the anode interface layer is revealed; all are shown to pose a threat to battery performance and stability. Mn2+, in particular, is shown to induce a thick, soft, and unstable SEI layer, which is known to cause severe degradation of batteries, while Co2+ and Ni2+ significantly impact interfacial conductivity. When transition metal ions are mixed, SEI degradation is amplified, suggesting a synergistic effect on the cell stability. Hence, by uncovering the roles these cathode degradation products play in operational batteries, we have provided a foundation upon which strategies to mitigate or eliminate these degradation products can be developed.
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Affiliation(s)
- Zhenyu Zhang
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 ORA, U.K.
- Renewable
Energy Group, Department of Engineering, Faculty of Environment, Science
and Economy, University of Exeter, Penryn Campus, Penryn, TR10 9FE, U.K.
| | - Samia Said
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
| | - Adam J. Lovett
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 ORA, U.K.
| | - Rhodri Jervis
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 ORA, U.K.
| | - Paul R. Shearing
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 ORA, U.K.
- Department
of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, U.K.
| | - Daniel J. L. Brett
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 ORA, U.K.
| | - Thomas S. Miller
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 ORA, U.K.
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3
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Shutt RRC, Aw ESY, Liu Q, Berry-Gair J, Lancaster HJ, Said S, Miller TS, Corà F, Howard CA, Clancy AJ. Investigating the mechanism of phosphorene nanoribbon synthesis by discharging black phosphorus intercalation compounds. Nanoscale 2024; 16:1742-1750. [PMID: 38197428 DOI: 10.1039/d3nr05416k] [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: 01/11/2024]
Abstract
Phosphorene nanoribbons (PNRs) can be synthesised in intrinsically scalable methods from intercalation of black phosphorus (BP), however, the mechanism of ribbonisation remains unclear. Herein, to investigate the point at which nanoribbons form, we decouple the two key synthesis steps: first, the formation of the BP intercalation compound, and second, the dissolution into a polar aprotic solvent. We find that both the lithium intercalant and the negative charge on the phosphorus host framework can be effectively removed by addition of phenyl cyanide to return BP and investigate whether fracturing to ribbons occurred after the first step. Further efforts to exfoliate mechanically with or without solvent reveal that the intercalation step does not form ribbons, indicating that an interaction between the amidic solvent and the intercalated phosphorus compound plays an important role in the formation of nanoribbons.
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Affiliation(s)
- Rebecca R C Shutt
- Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK.
| | - Eva S Y Aw
- Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK.
| | - Qili Liu
- Department of Chemistry, University College London, London, WC1E 0AJ, UK.
| | - Jasper Berry-Gair
- Department of Chemistry, University College London, London, WC1E 0AJ, UK.
| | - Hector J Lancaster
- Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK.
| | - Samia Said
- Electrochemical Innovation Laboratory, Department of Chemical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Thomas S Miller
- Electrochemical Innovation Laboratory, Department of Chemical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Furio Corà
- Department of Chemistry, University College London, London, WC1E 0AJ, UK.
| | - Christopher A Howard
- Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK.
| | - Adam J Clancy
- Department of Chemistry, University College London, London, WC1E 0AJ, UK.
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4
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Wilding MC, Benmore C, Headen TF, Di Mino C, Miller TS, Suter TM, Corà F, Clancy AJ, Sella A, McMillan P, Howard CA. The local ordering of polar solvents around crystalline carbon nitride nanosheets in solution. Philos Trans A Math Phys Eng Sci 2023; 381:20220337. [PMID: 37691462 PMCID: PMC10493548 DOI: 10.1098/rsta.2022.0337] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 08/03/2023] [Indexed: 09/12/2023]
Abstract
The crystalline graphitic carbon nitride, poly-triazine imide (PTI) is highly unusual among layered materials since it is spontaneously soluble in aprotic, polar solvents including dimethylformamide (DMF). The PTI material consists of layers of carbon nitride intercalated with LiBr. When dissolved, the resulting solutions consist of dissolved, luminescent single to multilayer nanosheets of around 60-125 nm in diameter and Li+ and Br- ions originating from the intercalating salt. To understand this unique solubility, the structure of these solutions has been investigated by high-energy X-ray and neutron diffraction. Although the diffraction patterns are dominated by inter-solvent correlations there are clear differences between the X-ray diffraction data of the PTI solution and the solvent in the 4-6 Å-1 range, with real space differences persisting to at least 10 Å. Structural modelling using both neutron and X-ray datasets as a constraint reveal the formation of distinct, dense solvation shells surrounding the nanoparticles with a layer of Br-close to the PTI-solvent interface. This solvent ordering provides a configuration that is energetically favourable underpinning thermodynamically driven PTI dissolution. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 2)'.
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Affiliation(s)
- Martin C. Wilding
- UK Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, Oxfordshire OX11 0QX, UK
| | - Chris Benmore
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - Thomas F. Headen
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Oxfordshire OX11 0QX, UK
| | - Camilla Di Mino
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Thomas S. Miller
- Electrochemical Innovation Laboratory, Department of Chemical Engineering, University College London, London WC1E 7JE, UK
| | - Theo M. Suter
- Electrochemical Innovation Laboratory, Department of Chemical Engineering, University College London, London WC1E 7JE, UK
| | - Furio Corà
- Department of Chemistry, University College London, London WC1E 6BT, UK
| | - Adam J. Clancy
- Department of Chemistry, University College London, London WC1E 6BT, UK
| | - Andrea Sella
- Department of Chemistry, University College London, London WC1E 6BT, UK
| | - Paul McMillan
- Department of Chemistry, University College London, London WC1E 6BT, UK
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5
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Lisowska K, Purser W, Chang F, Suter TM, Miller TS, Sella A, Howard CA, McMillan PF, Corà F, Clancy AJ. Amphoteric dissolution of two-dimensional polytriazine imide carbon nitrides in water. Philos Trans A Math Phys Eng Sci 2023; 381:20220339. [PMID: 37691463 PMCID: PMC10493549 DOI: 10.1098/rsta.2022.0339] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 05/18/2023] [Indexed: 09/12/2023]
Abstract
Crystalline two-dimensional carbon nitrides with polytriazine imide (PTI) structure are shown to act amphoterically, buffering both HCl and NaOH aqueous solutions, resulting in charged PTI layers that dissolve spontaneously in their aqueous media, particularly for the alkaline solutions. This provides a low energy, green route to their scalable solution processing. Protonation in acid is shown to occur at pyridinic nitrogens, stabilized by adjacent triazines, whereas deprotonation in base occurs primarily at basal plane NH bridges, although NH2 edge deprotonation is competitive. We conclude that mildly acidic or basic pHs are necessary to provide sufficient net charge on the nanosheets to promote dissolution, while avoiding high ion concentrations which screen the repulsion of like-charged PTI sheets in solution. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 2)'.
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Affiliation(s)
- Karolina Lisowska
- Department of Chemistry, University College London,London WC1E 0AJ, UK
| | - Will Purser
- Department of Chemistry, University College London,London WC1E 0AJ, UK
| | - Fuqiang Chang
- Department of Chemistry, University College London,London WC1E 0AJ, UK
| | - Theo M. Suter
- Department of Chemistry, University College London,London WC1E 0AJ, UK
- Department of Chemical Engineering, University College London, London WC1E 7JE, UK
| | - Thomas S. Miller
- Department of Chemical Engineering, University College London, London WC1E 7JE, UK
| | - Andrea Sella
- Department of Chemistry, University College London,London WC1E 0AJ, UK
| | | | - Paul F. McMillan
- Department of Chemistry, University College London,London WC1E 0AJ, UK
| | - Furio Corà
- Department of Chemistry, University College London,London WC1E 0AJ, UK
| | - Adam J. Clancy
- Department of Chemistry, University College London,London WC1E 0AJ, UK
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6
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Pandya R, Valzania L, Dorchies F, Xia F, Mc Hugh J, Mathieson A, Tan HJ, Parton TG, Godeffroy L, Mazloomian K, Miller TS, Kanoufi F, De Volder M, Tarascon JM, Gigan S, de Aguiar HB, Grimaud A. Three-dimensional operando optical imaging of particle and electrolyte heterogeneities inside Li-ion batteries. Nat Nanotechnol 2023; 18:1185-1194. [PMID: 37591934 DOI: 10.1038/s41565-023-01466-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 06/20/2023] [Indexed: 08/19/2023]
Abstract
Understanding (de)lithiation heterogeneities in battery materials is key to ensure optimal electrochemical performance. However, this remains challenging due to the three-dimensional morphology of electrode particles, the involvement of both solid- and liquid-phase reactants and a range of relevant timescales (seconds to hours). Here we overcome this problem and demonstrate the use of confocal microscopy for the simultaneous three-dimensional operando measurement of lithium-ion dynamics in individual agglomerate particles, and the electrolyte in batteries. We examine two technologically important cathode materials: LixCoO2 and LixNi0.8Mn0.1Co0.1O2. The surface-to-core transport velocity of Li-phase fronts and volume changes are captured as a function of cycling rate. Additionally, we visualize heterogeneities in the bulk and at agglomerate surfaces during cycling, and image microscopic liquid electrolyte concentration gradients. We discover that surface-limited reactions and intra-agglomerate competing rates control (de)lithiation and structural heterogeneities in agglomerate-based electrodes. Importantly, the conditions under which optical imaging can be performed inside the complex environments of battery electrodes are outlined.
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Affiliation(s)
- Raj Pandya
- Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, Collège de France, Paris, France.
- Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge, UK.
| | - Lorenzo Valzania
- Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, Collège de France, Paris, France
| | - Florian Dorchies
- Chimie du Solide et de l'Energie, UMR 8260, Collège de France, Paris, France
- Réseau sur le stockage Electrochimique de l'Energie (RS2E), Amiens, France
| | - Fei Xia
- Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, Collège de France, Paris, France
| | - Jeffrey Mc Hugh
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Labex Memolife, Université PSL, Paris, France
| | - Angus Mathieson
- Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Department of Engineering, University of Cambridge, Cambridge, UK
| | - Hwee Jien Tan
- Department of Engineering, University of Cambridge, Cambridge, UK
| | - Thomas G Parton
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | - Katrina Mazloomian
- Electrochemical Innovation Lab Department of Chemical Engineering, UCL, London, UK
| | - Thomas S Miller
- Electrochemical Innovation Lab Department of Chemical Engineering, UCL, London, UK
| | | | | | - Jean-Marie Tarascon
- Chimie du Solide et de l'Energie, UMR 8260, Collège de France, Paris, France
- Réseau sur le stockage Electrochimique de l'Energie (RS2E), Amiens, France
| | - Sylvain Gigan
- Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, Collège de France, Paris, France.
| | - Hilton B de Aguiar
- Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, Collège de France, Paris, France.
| | - Alexis Grimaud
- Chimie du Solide et de l'Energie, UMR 8260, Collège de France, Paris, France.
- Réseau sur le stockage Electrochimique de l'Energie (RS2E), Amiens, France.
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA, USA.
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7
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ShakeriHosseinabad F, Frost B, Said S, Xu C, Behnoudfar D, Amini K, Momodu D, Mahinpey N, Egberts P, Miller TS, Roberts EPL. Electrode Materials for Enhancing the Performance and Cycling Stability of Zinc Iodide Flow Batteries at High Current Densities. ACS Appl Mater Interfaces 2023. [PMID: 37433014 DOI: 10.1021/acsami.3c03785] [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: 07/13/2023]
Abstract
Aqueous redox flow battery systems that use a zinc negative electrode have a relatively high energy density. However, high current densities can lead to zinc dendrite growth and electrode polarization, which limit the battery's high power density and cyclability. In this study, a perforated copper foil with a high electrical conductivity was used on the negative side, combined with an electrocatalyst on the positive electrode in a zinc iodide flow battery. A significant improvement in the energy efficiency (ca. 10% vs using graphite felt on both sides) and cycling stability at a high current density of 40 mA cm-2 was observed. A long cycling stability with a high areal capacity of 222 mA h cm-2 is obtained in this study, which is the highest reported areal capacity for zinc-iodide aqueous flow batteries operating at high current density, in comparison to previous studies. Additionally, the use of a perforated copper foil anode in combination with a novel flow mode was discovered to achieve consistent cycling at exceedingly high current densities of >100 mA cm-2. In situ and ex situ characterization techniques, including in situ atomic force microscopy coupled with in situ optical microscopy and X-ray diffraction, are applied to clarify the relationship between zinc deposition morphology on the perforated copper foil and battery performance in two different flow field conditions. With a portion of the flow going through the perforations, a significantly more uniform and compact zinc deposition was observed compared to the case where all of the flow passed over the surface of the electrode. Results from modeling and simulation support the conclusion that the flow of a fraction of electrolyte through the electrode enhances mass transport, enabling a more compact deposit.
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Affiliation(s)
- Fatemeh ShakeriHosseinabad
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada
| | - Brandon Frost
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London WC1E 7JE, U.K
| | - Samia Said
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London WC1E 7JE, U.K
| | - Chaochen Xu
- Department Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Drive NW, Calgary AB T2N 1N4, Canada
| | - Diba Behnoudfar
- School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, Oregon 97331, United States
| | - Kiana Amini
- Harvard John A. Paulson School of Engineering and Applied Sciences, 29 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Damilola Momodu
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada
| | - Nader Mahinpey
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada
| | - Philip Egberts
- Department Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Drive NW, Calgary AB T2N 1N4, Canada
| | - Thomas S Miller
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London WC1E 7JE, U.K
| | - Edward P L Roberts
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada
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8
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Soni R, Spadoni D, Shearing PR, Brett DJL, Lekakou C, Cai Q, Robinson JB, Miller TS. Deploying Proteins as Electrolyte Additives in Li-S Batteries: The Multifunctional Role of Fibroin in Improving Cell Performance. ACS Appl Energy Mater 2023; 6:5671-5680. [PMID: 37323207 PMCID: PMC10266332 DOI: 10.1021/acsaem.2c04131] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 05/16/2023] [Indexed: 06/17/2023]
Abstract
It is widely accepted that the commercial application of lithium-sulfur batteries is inhibited by their short cycle life, which is primarily caused by a combination of Li dendrite formation and active material loss due to polysulfide shuttling. Unfortunately, while numerous approaches to overcome these problems have been reported, most are unscalable and hence further hinder Li-S battery commercialization. Most approaches suggested also only tackle one of the primary mechanisms of cell degradation and failure. Here, we demonstrate that the use of a simple protein, fibroin, as an electrolyte additive can both prevent Li dendrite formation and minimize active material loss to enable high capacity and long cycle life (up to 500 cycles) in Li-S batteries, without inhibiting the rate performance of the cell. Through a combination of experiments and molecular dynamics (MD) simulations, it is demonstrated that the fibroin plays a dual role, both binding to polysulfides to hinder their transport from the cathode and passivating the Li anode to minimize dendrite nucleation and growth. Most importantly, as fibroin is inexpensive and can be simply introduced to the cell via the electrolyte, this work offers a route toward practical industrial applications of a viable Li-S battery system.
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Affiliation(s)
- Roby Soni
- Department
of Chemical Engineering, Electrochemical Innovation Lab, University College London, London WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, U.K.
| | - Damiano Spadoni
- The
Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, U.K.
- School
of Mechanical Engineering Sciences, University
of Surrey, Guildford GU2 7XH, U.K.
- Department
of Chemical Engineering, University of Surrey, Guildford GU2 7XH, U.K.
| | - Paul R. Shearing
- Department
of Chemical Engineering, Electrochemical Innovation Lab, University College London, London WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, U.K.
| | - Dan J. L. Brett
- Department
of Chemical Engineering, Electrochemical Innovation Lab, University College London, London WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, U.K.
| | - Constantina Lekakou
- The
Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, U.K.
- School
of Mechanical Engineering Sciences, University
of Surrey, Guildford GU2 7XH, U.K.
| | - Qiong Cai
- The
Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, U.K.
- Department
of Chemical Engineering, University of Surrey, Guildford GU2 7XH, U.K.
| | - James B. Robinson
- Department
of Chemical Engineering, Electrochemical Innovation Lab, University College London, London WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, U.K.
| | - Thomas S. Miller
- Department
of Chemical Engineering, Electrochemical Innovation Lab, University College London, London WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, U.K.
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9
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Said S, Zhang Z, Shutt RRC, Lancaster HJ, Brett DJL, Howard CA, Miller TS. Black Phosphorus Degradation during Intercalation and Alloying in Batteries. ACS Nano 2023; 17:6220-6233. [PMID: 36972510 PMCID: PMC10100570 DOI: 10.1021/acsnano.2c08776] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 03/16/2023] [Indexed: 06/18/2023]
Abstract
Numerous layered materials are being recognized as promising candidates for high-performance alkali-ion battery anodes, but black phosphorus (BP) has received particular attention. This is due to its high specific capacity, due to a mixed alkali-ion storage mechanism (intercalation-alloying), and fast alkali-ion transport within its layers. Unfortunately, BP based batteries are also commonly associated with serious irreversible losses and poor cycling stability. This is known to be linked to alloying, but there is little experimental evidence of the morphological, mechanical, or chemical changes that BP undergoes in operational cells and thus little understanding of the factors that must be mitigated to optimize performance. Here the degradation mechanisms of BP alkali-ion battery anodes are revealed through operando electrochemical atomic force microscopy (EC-AFM) and ex situ spectroscopy. Among other phenomena, BP is observed to wrinkle and deform during intercalation but suffers from complete structural breakdown upon alloying. The solid electrolyte interphase (SEI) is also found to be unstable, nucleating at defects before spreading across the basal planes but then disintegrating upon desodiation, even above alloying potentials. By directly linking these localized phenomena with the whole-cell performance, we can now engineer stabilizing protocols for next-generation high-capacity alkali-ion batteries.
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Affiliation(s)
- Samia Said
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
| | - Zhenyu Zhang
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 ORA, U.K.
| | - Rebecca R. C. Shutt
- Department
of Physics & Astronomy, University College
London, Gower Street, London, WC1E 6BT, U.K.
| | - Hector J. Lancaster
- Department
of Physics & Astronomy, University College
London, Gower Street, London, WC1E 6BT, U.K.
| | - Dan J. L. Brett
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 ORA, U.K.
| | - Christopher A. Howard
- Department
of Physics & Astronomy, University College
London, Gower Street, London, WC1E 6BT, U.K.
| | - Thomas S. Miller
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, U.K.
- The
Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 ORA, U.K.
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10
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Chen G, Chen J, Zhao S, He G, Miller TS. Pseudohexagonal Nb 2O 5 Anodes for Fast-Charging Potassium-Ion Batteries. ACS Appl Mater Interfaces 2023; 15:16664-16672. [PMID: 36943902 PMCID: PMC10080539 DOI: 10.1021/acsami.2c21490] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 03/10/2023] [Indexed: 06/18/2023]
Abstract
High-rate batteries will play a vital role in future energy storage systems, yet while good progress is being made in the development of high-rate lithium-ion batteries, there is less progress with post-lithium-ion chemistry. In this study, we demonstrate that pseudohexagonal Nb2O5(TT-Nb2O5) can offer a high specific capacity (179 mAh g-1 ∼ 0.3C), good lifetime, and an excellent rate performance (72 mAh g-1 at ∼15C) in potassium-ion batteries (KIBs), when it is composited with a highly conductive carbon framework; this is the first reported investigation of TT-Nb2O5 for KIBs. Specifically, multiwalled carbon nanotubes are strongly tethered to Nb2O5 via glucose-derived carbon (Nb2O5@CNT) by a one-step hydrothermal method, which results in highly conductive and porous needle-like structures. This work therefore offers a route for the scalable production of a viable KIB anode material and hence improves the feasibility of fast-charging KIBs for future applications.
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11
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Marinov AD, Bravo Priegue L, Shah AR, Miller TS, Howard CA, Hinds G, Shearing PR, Cullen PL, Brett DJL. Ex Situ Characterization of 1T/2H MoS 2 and Their Carbon Composites for Energy Applications, a Review. ACS Nano 2023; 17:5163-5186. [PMID: 36926849 PMCID: PMC10062033 DOI: 10.1021/acsnano.2c08913] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
The growing interest in the development of next-generation net zero energy systems has led to the expansion of molybdenum disulfide (MoS2) research in this area. This activity has resulted in a wide range of manufacturing/synthesis methods, controllable morphologies, diverse carbonaceous composite structures, a multitude of applicable characterization techniques, and multiple energy applications for MoS2. To assess the literature trends, 37,347 MoS2 research articles from Web of Science were text scanned to classify articles according to energy application research and characterization techniques employed. Within the review, characterization techniques are grouped under the following categories: morphology, crystal structure, composition, and chemistry. The most common characterization techniques identified through text scanning are recommended as the base fingerprint for MoS2 samples. These include: scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Similarly, XPS and Raman spectroscopy are suggested for 2H or 1T MoS2 phase confirmation. We provide guidance on the collection and presentation of MoS2 characterization data. This includes how to effectively combine multiple characterization techniques, considering the sample area probed by each technique and their statistical significance, and the benefit of using reference samples. For ease of access for future experimental comparison, key numeric MoS2 characterization values are tabulated and major literature discrepancies or currently debated characterization disputes are highlighted.
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Affiliation(s)
- Alexandar D Marinov
- Electrochemical Innovation Laboratory (EIL), Department of Chemical Engineering, University College London (UCL), Gower Street, London WC1E 6BT, U.K
| | | | - Ami R Shah
- Electrochemical Innovation Laboratory (EIL), Department of Chemical Engineering, University College London (UCL), Gower Street, London WC1E 6BT, U.K
| | - Thomas S Miller
- Electrochemical Innovation Laboratory (EIL), Department of Chemical Engineering, University College London (UCL), Gower Street, London WC1E 6BT, U.K
| | - Christopher A Howard
- Department of Physics & Astronomy, University College London (UCL), Gower Street, London WC1E 6BT, U.K
| | - Gareth Hinds
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, U.K
| | - Paul R Shearing
- Electrochemical Innovation Laboratory (EIL), Department of Chemical Engineering, University College London (UCL), Gower Street, London WC1E 6BT, U.K
| | - Patrick L Cullen
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, U.K
| | - Dan J L Brett
- Electrochemical Innovation Laboratory (EIL), Department of Chemical Engineering, University College London (UCL), Gower Street, London WC1E 6BT, U.K
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12
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Vadhva P, Gill TE, Cruddos JH, Said S, Siniscalchi M, Narayanan S, Pasta M, Miller TS, Rettie AJE. Engineering Solution-Processed Non-Crystalline Solid Electrolytes for Li Metal Batteries. Chem Mater 2023; 35:1168-1176. [PMID: 36818586 PMCID: PMC9933431 DOI: 10.1021/acs.chemmater.2c03071] [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: 10/17/2022] [Revised: 12/22/2022] [Indexed: 06/18/2023]
Abstract
Non-crystalline Li-ion solid electrolytes (SEs), such as lithium phosphorus oxynitride, can uniquely enable high-rate solid-state battery operation over thousands of cycles in thin film form. However, they are typically produced by expensive and low throughput vacuum deposition, limiting their wide application and study. Here, we report non-crystalline SEs of composition Li-Al-P-O (LAPO) with ionic conductivities > 10-7 S cm-1 at room temperature made by spin coating from aqueous solutions and subsequent annealing in air. Homogenous, dense, flat layers can be synthesized with submicrometer thickness at temperatures as low as 230 °C. Control of the composition is shown to significantly affect the ionic conductivity, with increased Li and decreased P content being optimal, while higher annealing temperatures result in decreased ionic conductivity. Activation energy analysis reveals a Li-ion hopping barrier of ≈0.4 eV. Additionally, these SEs exhibit low room temperature electronic conductivity (< 10-11 S cm-1) and a moderate Young's modulus of ≈54 GPa, which may be beneficial in preventing Li dendrite formation. In contact with Li metal, LAPO is found to form a stable but high impedance passivation layer comprised of Al metal, Li-P, and Li-O species. These findings should be of value when engineering non-crystalline SEs for Li-metal batteries with high energy and power densities.
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Affiliation(s)
- Pooja Vadhva
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, LondonWC1E 6DH,United Kingdom
| | - Thomas E. Gill
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, LondonWC1E 6DH,United Kingdom
| | - Joshua H. Cruddos
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, LondonWC1E 6DH,United Kingdom
- The
Faraday Institution Quad One, Harwell Science
and Innovation Campus, DidcotOX11 0RA,United
Kingdom
| | - Samia Said
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, LondonWC1E 6DH,United Kingdom
| | - Marco Siniscalchi
- Department
of Materials, University of Oxford, OX1 3PHOxford, United Kingdom
| | - Sudarshan Narayanan
- The
Faraday Institution Quad One, Harwell Science
and Innovation Campus, DidcotOX11 0RA,United
Kingdom
- Department
of Materials, University of Oxford, OX1 3PHOxford, United Kingdom
| | - Mauro Pasta
- The
Faraday Institution Quad One, Harwell Science
and Innovation Campus, DidcotOX11 0RA,United
Kingdom
- Department
of Materials, University of Oxford, OX1 3PHOxford, United Kingdom
| | - Thomas S. Miller
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, LondonWC1E 6DH,United Kingdom
- The
Faraday Institution Quad One, Harwell Science
and Innovation Campus, DidcotOX11 0RA,United
Kingdom
| | - Alexander J. E. Rettie
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, LondonWC1E 6DH,United Kingdom
- The
Faraday Institution Quad One, Harwell Science
and Innovation Campus, DidcotOX11 0RA,United
Kingdom
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13
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Liu M, Yao L, Ji Y, Zhang M, Gan Y, Cai Y, Li H, Zhao W, Zhao Y, Zou Z, Qin R, Wang Y, Liu L, Liu H, Yang K, Miller TS, Pan F, Yang J. Nanoscale Ultrafine Zinc Metal Anodes for High Stability Aqueous Zinc Ion Batteries. Nano Lett 2023; 23:541-549. [PMID: 36594815 PMCID: PMC9881152 DOI: 10.1021/acs.nanolett.2c03919] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 12/09/2022] [Indexed: 06/17/2023]
Abstract
Aqueous Zn batteries (AZBs) are a promising energy storage technology, due to their high theoretical capacity, low redox potential, and safety. However, dendrite growth and parasitic reactions occurring at the surface of metallic Zn result in severe instability. Here we report a new method to achieve ultrafine Zn nanograin anodes by using ethylene glycol monomethyl ether (EGME) molecules to manipulate zinc nucleation and growth processes. It is demonstrated that EGME complexes with Zn2+ to moderately increase the driving force for nucleation, as well as adsorbs on the Zn surface to prevent H-corrosion and dendritic protuberances by refining the grains. As a result, the nanoscale anode delivers high Coulombic efficiency (ca. 99.5%), long-term cycle life (over 366 days and 8800 cycles), and outstanding compatibility with state-of-the-art cathodes (ZnVO and AC) in full cells. This work offers a new route for interfacial engineering in aqueous metal-ion batteries, with significant implications for the commercial future of AZBs.
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Affiliation(s)
- Mingqiang Liu
- Guangdong
Research Center for Interfacial Engineering of Functional Materials,
College of Materials Science and Engineering, Shenzhen University, Shenzhen518060, P. R. China
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE, U.K.
| | - Lu Yao
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
| | - Yuchen Ji
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
| | - Mingzheng Zhang
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
| | - Yihang Gan
- Guangdong
Research Center for Interfacial Engineering of Functional Materials,
College of Materials Science and Engineering, Shenzhen University, Shenzhen518060, P. R. China
| | - Yulu Cai
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
| | - Hongyang Li
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
| | - Wenguang Zhao
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
| | - Yan Zhao
- Department
of Mechanical Engineering, Imperial College
London, London, SW7 2AZ, U.K.
| | - Zexin Zou
- Guangdong
Research Center for Interfacial Engineering of Functional Materials,
College of Materials Science and Engineering, Shenzhen University, Shenzhen518060, P. R. China
| | - Runzhi Qin
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
| | - Yuetao Wang
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
| | - Lele Liu
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
| | - Hao Liu
- School
of Chemical Engineering and Advanced Materials, The University of Adelaide, North
Terrace, South Australia5005, Australia
| | - Kai Yang
- Department
of Electrical and Electronic Engineering, University of Surrey, Guildford, SurreyGU2 7XH, U.K.
| | - Thomas S. Miller
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE, U.K.
| | - Feng Pan
- School
of Advanced Materials, Peking University
Shenzhen Graduate School, Shenzhen518055, P. R. China
| | - Jinlong Yang
- Guangdong
Research Center for Interfacial Engineering of Functional Materials,
College of Materials Science and Engineering, Shenzhen University, Shenzhen518060, P. R. China
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14
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Chen G, Chen J, Parkin IP, He G, Miller TS. Pseudohexagonal Nb2O5 decorated carbon nanotubes as a high‐performance composite anode for sodium‐ion batteries. ChemElectroChem 2022. [DOI: 10.1002/celc.202200800] [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)
- Guanxu Chen
- UCL: University College London Chemical Engineering UNITED KINGDOM
| | - Jintao Chen
- UCL: University College London Chemistry UNITED KINGDOM
| | - Ivan P. Parkin
- UCL: University College London Chemistry Department of ChemistryUniversity College London WC1H 0AJ London UNITED KINGDOM
| | - Guanjie He
- University College London Chemistry Department of Chemistry - University College London - 20 Gordon Street - London WC1H 0AJ London UNITED KINGDOM
| | - Thomas S. Miller
- UCL: University College London Chemical Engineering UNITED KINGDOM
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15
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Mastronardi V, Magliocca E, Gullon JS, Brescia R, Pompa PP, Miller TS, Moglianetti M. Ultrasmall, Coating-Free, Pyramidal Platinum Nanoparticles for High Stability Fuel Cell Oxygen Reduction. ACS Appl Mater Interfaces 2022; 14:36570-36581. [PMID: 35920442 PMCID: PMC9975930 DOI: 10.1021/acsami.2c07738] [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] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
Ultrasmall (<5 nm diameter) noble metal nanoparticles with a high fraction of {111} surface domains are of fundamental and practical interest as electrocatalysts, especially in fuel cells; the nanomaterial surface structure dictates its catalytic properties, including kinetics and stability. However, the synthesis of size-controlled, pure Pt-shaped nanocatalysts has remained a formidable chemical challenge. There is an urgent need for an industrially scalable method for their production. Here, a one-step approach is presented for the preparation of single-crystal pyramidal nanocatalysts with a high fraction of {111} surface domains and a diameter below 4 nm. This is achieved by harnessing the shape-directing effect of citrate molecules, together with the strict control of oxidative etching while avoiding polymers, surfactants, and organic solvents. These catalysts exhibit significantly enhanced durability while, providing equivalent current and power densities to highly optimized commercial Pt/C catalysts at the beginning of life (BOL). This is even the case when they are tested in full polymer electrolyte membrane fuel cells (PEMFCs), as opposed to rotating disk experiments that artificially enhance electrode kinetics and minimize degradation. This demonstrates that the {111} surface domains in pyramidal Pt nanoparticles (as opposed to spherical Pt nanoparticles) can improve aggregation/corrosion resistance in realistic fuel cell conditions, leading to a significant improvement in membrane electrode assembly (MEA) stability and lifetime.
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Affiliation(s)
- Valentina Mastronardi
- Nanobiointeractions
& Nanodiagnostics, Istituto Italiano
di Tecnologia, Via Morego 30, 16163 Genova, Italy
- Department
of Chemistry and Industrial Chemistry, University
of Genova, Via Dodecaneso
31, 16146 Genova, Italy
| | - Emanuele Magliocca
- Electrochemical
Innovation Laboratory, Department of Chemical Engineering, University College London, Torrington Place, WC1E 7JE London, U.K.
| | - José Solla Gullon
- Institute
of Electrochemistry, University of Alicante, Apdo. 99, E-03080 Alicante, Spain
| | - Rosaria Brescia
- Electron
Microscopy Facility, Istituto Italiano di
Tecnologia, Via Morego
30, 16163 Genova, Italy
| | - Pier Paolo Pompa
- Nanobiointeractions
& Nanodiagnostics, Istituto Italiano
di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Thomas S. Miller
- Electrochemical
Innovation Laboratory, Department of Chemical Engineering, University College London, Torrington Place, WC1E 7JE London, U.K.
| | - Mauro Moglianetti
- Nanobiointeractions
& Nanodiagnostics, Istituto Italiano
di Tecnologia, Via Morego 30, 16163 Genova, Italy
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16
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Foglia F, Berrod Q, Clancy AJ, Smith K, Gebel G, Sakai VG, Appel M, Zanotti JM, Tyagi M, Mahmoudi N, Miller TS, Varcoe JR, Periasamy AP, Brett DJL, Shearing PR, Lyonnard S, McMillan PF. Disentangling water, ion and polymer dynamics in an anion exchange membrane. Nat Mater 2022; 21:555-563. [PMID: 35301475 DOI: 10.1038/s41563-022-01197-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/11/2022] [Indexed: 05/12/2023]
Abstract
Semipermeable polymeric anion exchange membranes are essential for separation, filtration and energy conversion technologies including reverse electrodialysis systems that produce energy from salinity gradients, fuel cells to generate electrical power from the electrochemical reaction between hydrogen and oxygen, and water electrolyser systems that provide H2 fuel. Anion exchange membrane fuel cells and anion exchange membrane water electrolysers rely on the membrane to transport OH- ions between the cathode and anode in a process that involves cooperative interactions with H2O molecules and polymer dynamics. Understanding and controlling the interactions between the relaxation and diffusional processes pose a main scientific and critical membrane design challenge. Here quasi-elastic neutron scattering is applied over a wide range of timescales (100-103 ps) to disentangle the water, polymer relaxation and OH- diffusional dynamics in commercially available anion exchange membranes (Fumatech FAD-55) designed for selective anion transport across different technology platforms, using the concept of serial decoupling of relaxation and diffusional processes to analyse the data. Preliminary data are also reported for a laboratory-prepared anion exchange membrane especially designed for fuel cell applications.
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Affiliation(s)
- Fabrizia Foglia
- Department of Chemistry, Christopher Ingold Laboratory, University College London, London, UK.
| | - Quentin Berrod
- Université Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, Grenoble, France
| | - Adam J Clancy
- Department of Chemistry, Christopher Ingold Laboratory, University College London, London, UK
| | - Keenan Smith
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, UK
| | - Gérard Gebel
- Université Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, Grenoble, France
| | - Victoria García Sakai
- ISIS Neutron and Muon Source, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Chilton, UK
| | | | - Jean-Marc Zanotti
- Laboratoire Léon Brillouin (CEA-CNRS), Université Paris-Saclay, CEA Saclay, Gif-sur-Yvette Cedex, France
| | - Madhusudan Tyagi
- NIST Center for Neutron Research (NCNR), National Institute of Standards and Technology, Gaithersburg, MD, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD, USA
| | - Najet Mahmoudi
- ISIS Neutron and Muon Source, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Chilton, UK
| | - Thomas S Miller
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, UK
| | - John R Varcoe
- Department of Chemistry, University of Surrey, Guildford, UK
| | | | - Daniel J L Brett
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, UK
| | - Paul R Shearing
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, UK
| | - Sandrine Lyonnard
- Université Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, Grenoble, France.
| | - Paul F McMillan
- Department of Chemistry, Christopher Ingold Laboratory, University College London, London, UK
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17
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Leach AS, Hack J, Amboage M, Diaz-Moreno S, Huang H, Cullen PL, Wilding M, Magliocca E, Miller TS, Howard CA, Brett DJL, Shearing PR, McMillan PF, Russell AE, Jervis R. A novel fuel cell design for operandoenergy-dispersive x-ray absorption measurements. J Phys Condens Matter 2021; 33:314002. [PMID: 34030140 DOI: 10.1088/1361-648x/ac0476] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/24/2021] [Indexed: 06/12/2023]
Abstract
A polymer electrolyte fuel cell has been designed to allowoperandox-ray absorption spectroscopy (XAS) measurements of catalysts. The cell has been developed to operate under standard fuel cell conditions, with elevated temperatures and humidification of the gas-phase reactants, both of which greatly impact the catalyst utilisation. X-ray windows in the endplates of the cell facilitate collection of XAS spectra during fuel cell operation while maintaining good compression in the area of measurement. Results of polarisation curves and cyclic voltammograms showed that theoperandocell performs well as a fuel cell, while also providing XAS data of suitable quality for robust XANES analysis. The cell has produced comparable XAS results when performing a cyclic voltammogram to an establishedin situcell when measuring the Pt LIII edge. Similar trends of Pt oxidation, and reduction of the formed Pt oxide, have been presented with a time resolution of 5 s for each spectrum, paving the way for time-resolved spectral measurements of fuel cell catalysts in a fully-operating fuel cell.
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Affiliation(s)
- A S Leach
- Electrochemical Innovation Lab, Department of Chemical Engineering, UCL, London WC1E 7JE, United Kingdom
| | - J Hack
- Electrochemical Innovation Lab, Department of Chemical Engineering, UCL, London WC1E 7JE, United Kingdom
| | - M Amboage
- Diamond Light Source, Didcot, Oxon, OX11 0DE, United Kingdom
| | - S Diaz-Moreno
- Diamond Light Source, Didcot, Oxon, OX11 0DE, United Kingdom
| | - H Huang
- School of Chemistry, University of Southampton, University Road, Southampton SO17 1BJ, United Kingdom
| | - P L Cullen
- Electrochemical Innovation Lab, Department of Chemical Engineering, UCL, London WC1E 7JE, United Kingdom
- School of Engineering and Materials Science (SEMS) and Material Research Institute, Queen Mary University of London, London, E1 4NS, United Kingdom
| | - M Wilding
- UK Catalysis Hub, Research Complex at Harwell, Harwell Campus, OX11 0FA, United Kingdom
| | - E Magliocca
- Electrochemical Innovation Lab, Department of Chemical Engineering, UCL, London WC1E 7JE, United Kingdom
| | - T S Miller
- Electrochemical Innovation Lab, Department of Chemical Engineering, UCL, London WC1E 7JE, United Kingdom
| | - C A Howard
- Department of Physics & Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - D J L Brett
- Electrochemical Innovation Lab, Department of Chemical Engineering, UCL, London WC1E 7JE, United Kingdom
| | - P R Shearing
- Electrochemical Innovation Lab, Department of Chemical Engineering, UCL, London WC1E 7JE, United Kingdom
| | - P F McMillan
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, United Kingdom
| | - A E Russell
- School of Chemistry, University of Southampton, University Road, Southampton SO17 1BJ, United Kingdom
| | - R Jervis
- Electrochemical Innovation Lab, Department of Chemical Engineering, UCL, London WC1E 7JE, United Kingdom
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18
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Foglia F, Clancy AJ, Berry-Gair J, Lisowska K, Wilding MC, Suter TM, Miller TS, Smith K, Demmel F, Appel M, Sakai VG, Sella A, Howard CA, Tyagi M, Corà F, McMillan PF. Aquaporin-like water transport in nanoporous crystalline layered carbon nitride. Sci Adv 2020; 6:eabb6011. [PMID: 32978165 PMCID: PMC7518864 DOI: 10.1126/sciadv.abb6011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
Designing next-generation fuel cell and filtration devices requires the development of nanoporous materials that allow rapid and reversible uptake and directed transport of water molecules. Here, we combine neutron spectroscopy and first-principles calculations to demonstrate rapid transport of molecular H2O through nanometer-sized voids ordered within the layers of crystalline carbon nitride with a polytriazine imide structure. The transport mechanism involves a sequence of molecular orientation reversals directed by hydrogen-bonding interactions as the neutral molecules traverse the interlayer gap and pass through the intralayer voids that show similarities with the transport of water through transmembrane aquaporin channels in biological systems. The results suggest that nanoporous layered carbon nitrides can be useful for developing high-performance membranes.
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Affiliation(s)
- Fabrizia Foglia
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Adam J Clancy
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Jasper Berry-Gair
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Karolina Lisowska
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Martin C Wilding
- University of Manchester at Harwell, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Theo M Suter
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Thomas S Miller
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Keenan Smith
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Franz Demmel
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Chilton OX11 0QX, UK
| | - Markus Appel
- Institut Laue Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble CEDEX 9, France
| | - Victoria García Sakai
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Chilton OX11 0QX, UK
| | - Andrea Sella
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Christopher A Howard
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Madhusudan Tyagi
- NIST Center for Neutron Research (NCNR), National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA
| | - Furio Corà
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK
| | - Paul F McMillan
- Department of Chemistry, Christopher Ingold Laboratory, University College London, 20 Gordon St., London WC1H 0AJ, UK.
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P.E. S, Miller TS, Meng L, Unwin PR, Macpherson JV. Quantitative trace level voltammetry in the presence of electrode fouling agents: Comparison of single-walled carbon nanotube network electrodes and screen-printed carbon electrodes. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.114137] [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: 10/24/2022]
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20
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Zhang Z, Smith K, Jervis R, Shearing PR, Miller TS, Brett DJL. Operando Electrochemical Atomic Force Microscopy of Solid-Electrolyte Interphase Formation on Graphite Anodes: The Evolution of SEI Morphology and Mechanical Properties. ACS Appl Mater Interfaces 2020; 12:35132-35141. [PMID: 32657567 PMCID: PMC7458363 DOI: 10.1021/acsami.0c11190] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 07/13/2020] [Indexed: 05/19/2023]
Abstract
Understanding and ultimately controlling the properties of the solid-electrolyte interphase (SEI) layer at the graphite anode/liquid electrolyte boundary are of great significance for maximizing the performance and lifetime of lithium-ion batteries (LIBs). However, comprehensive in situ monitoring of SEI formation and evolution, alongside measurement of the corresponding mechanical properties, is challenging due to the limitations of the characterization techniques commonly used. This work provides a new insight into SEI formation during the first lithiation and delithiation of graphite battery anodes using operando electrochemical atomic force microscopy (EC-AFM). Highly oriented pyrolytic graphite (HOPG) is investigated first as a model system, exhibiting unique morphological and nanomechanical behavior dependent on the various electrolytes and commercially relevant additives used. Then, to validate these findings with respect to real-world battery electrodes, operando EC-AFM of individual graphite particles like those in commercial systems are studied. Vinylene carbonate (VC) and fluoroethylene carbonate (FEC) are shown to be effective additives to enhance SEI layer stability in 1 M LiPF6/ethylene carbonate/ethyl methyl carbonate (EC/EMC) electrolytes, attributed to their role in improving its structure, density, and mechanical strength. This work therefore presents an unambiguous picture of SEI formation in a real battery environment, contributes a comprehensive insight into SEI formation of electrode materials, and provides a visible understanding of the influence of electrolyte additives on SEI formation.
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Affiliation(s)
- Zhenyu Zhang
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, WC1E 7JE London, U.K.
- The Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, OX11 ORA Didcot, U.K.
| | - Keenan Smith
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, WC1E 7JE London, U.K.
| | - Rhodri Jervis
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, WC1E 7JE London, U.K.
- The Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, OX11 ORA Didcot, U.K.
| | - Paul R. Shearing
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, WC1E 7JE London, U.K.
- The Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, OX11 ORA Didcot, U.K.
| | - Thomas S. Miller
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, WC1E 7JE London, U.K.
- The Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, OX11 ORA Didcot, U.K.
| | - Daniel J. L. Brett
- Electrochemical
Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, WC1E 7JE London, U.K.
- The Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, OX11 ORA Didcot, U.K.
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21
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Goldman-Yassen AE, Goodrich JT, Miller TS, Farinhas JM. Preoperative Evaluation of Craniopagus Twins: Anatomy, Imaging Techniques, and Surgical Management. AJNR Am J Neuroradiol 2020; 41:951-959. [PMID: 32439641 DOI: 10.3174/ajnr.a6571] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/10/2020] [Indexed: 11/07/2022]
Abstract
Craniopagus twins are a rare congenital malformation in which twins are conjoined at the head. Although there is high prenatal and postnatal mortality for craniopagus twins, successful separation has become more common due to advances in neuroimaging, neuroanesthesia, and neurosurgical techniques. Joined brain tissue, shared arteries and veins, and defects in the skull and dura make surgery technically challenging, and neuroimaging plays an important role in preoperative planning. Drawing on our experience from consultation for multiple successful separations of craniopagus twins, we discuss what radiologists need to know about the anatomy, classification, imaging techniques, and surgical management of craniopagus twins.
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Affiliation(s)
- A E Goldman-Yassen
- From the Department of Radiology (A.E.G.-Y.), Children's Hospital of Philadelphia, Philadelphia, Pennsylvania .,Departments of Radiology (A.E.G.-Y., J.M.F.)
| | - J T Goodrich
- Neurosurgery (J.T.G.), Montefiore Medical Center, Bronx, New York
| | - T S Miller
- Department of Radiology (T.S.M.), Stamford Hospital, Stamford, Connecticut
| | - J M Farinhas
- Departments of Radiology (A.E.G.-Y., J.M.F.).,Department of Radiology (J.M.F.), Moffitt Cancer Center Tampa, Florida
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22
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Dizajghorbani-Aghdam H, Miller TS, Malekfar R, McMillan PF. SERS-Active Cu Nanoparticles on Carbon Nitride Support Fabricated Using Pulsed Laser Ablation. Nanomaterials (Basel) 2019; 9:E1223. [PMID: 31470589 PMCID: PMC6780541 DOI: 10.3390/nano9091223] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/23/2019] [Accepted: 08/23/2019] [Indexed: 11/30/2022]
Abstract
We report a single-step route to co-deposit Cu nanoparticles with a graphitic carbon nitride (gCN) support using nanosecond Ce:Nd:YAG pulsed laser ablation from a Cu metal target coated using acetonitrile (CH3CN). The resulting Cu/gCN hybrids showed strong optical absorption in the visible to near-IR range and exhibited surface-enhanced Raman or resonance Raman scattering (SERS or SERRS) enhancement for crystal violet (CV), methylene blue (MB), and rhodamine 6G (R6G) used as probe analyte molecules adsorbed on the surface. We have characterized the Cu nanoparticles and the nature of the gCN support materials using a range of spectroscopic, structural, and compositional analysis techniques.
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Affiliation(s)
- Hossein Dizajghorbani-Aghdam
- Atomic and Molecular Group, Physics Department, Faculty of Basic Sciences, Tarbiat Modares University, Tehran 14115-175, Iran
| | - Thomas S Miller
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Rasoul Malekfar
- Atomic and Molecular Group, Physics Department, Faculty of Basic Sciences, Tarbiat Modares University, Tehran 14115-175, Iran.
| | - Paul F McMillan
- Department of Chemistry, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
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23
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Suter TM, Miller TS, Cockcroft JK, Aliev AE, Wilding MC, Sella A, Corà F, Howard CA, McMillan PF. Formation of an ion-free crystalline carbon nitride and its reversible intercalation with ionic species and molecular water. Chem Sci 2019; 10:2519-2528. [PMID: 30881682 PMCID: PMC6385848 DOI: 10.1039/c8sc05232h] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [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: 11/23/2018] [Accepted: 12/20/2018] [Indexed: 11/21/2022] Open
Abstract
Crystalline layered carbon nitrides can be inter-converted by simple ion exchange process allowing their properties to be tuned.
The development of processes to tune the properties of materials is essential for the progression of next-generation technologies for catalysis, optoelectronics and sustainability including energy harvesting and conversion. Layered carbon nitrides have also been identified as of significant interest within these fields of application. However, most carbon nitride materials studied to date have poor crystallinity and therefore their properties cannot be readily controlled or easily related to their molecular level or nanoscale structures. Here we report a process for forming a range of crystalline layered carbon nitrides with polytriazine imide (PTI) structures that can be interconverted by simple ion exchange processes, permitting the tunability of their optoelectronic and chemical properties. Notable outcomes of our work are (a) the creation of a crystalline, guest-ion-free PTI compound that (b) can be re-intercalated with ions or molecules using “soft chemistry” approaches. This includes the intercalation of HCl, demonstrating a new ambient pressure route to the layered PTI·xHCl material that was previously only available by a high-pressure-high-temperature route (c). Our work also shows (d) that the intercalant-free (IF-) PTI material spontaneously absorbs up to 10 weight% H2O from the ambient atmosphere and that this process is reversible, leading to potential applications for membranes and water capture in dry environments.
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Affiliation(s)
- Theo M Suter
- Department of Chemistry , University College London , Christopher Ingold Building, 20 Gordon Street , WC1H 0AJ , London , UK . .,Electrochemical Innovation Lab , Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , UK .
| | - Thomas S Miller
- Electrochemical Innovation Lab , Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , UK .
| | - Jeremy K Cockcroft
- Department of Chemistry , University College London , Christopher Ingold Building, 20 Gordon Street , WC1H 0AJ , London , UK .
| | - Abil E Aliev
- Department of Chemistry , University College London , Christopher Ingold Building, 20 Gordon Street , WC1H 0AJ , London , UK .
| | - Martin C Wilding
- Department of Chemistry , University College London , Christopher Ingold Building, 20 Gordon Street , WC1H 0AJ , London , UK . .,Materials and Engineering Research Institute , Sheffield Hallam University , City Campus , Howard Street , Sheffield , S1 1WB , UK
| | - Andrea Sella
- Department of Chemistry , University College London , Christopher Ingold Building, 20 Gordon Street , WC1H 0AJ , London , UK .
| | - Furio Corà
- Department of Chemistry , University College London , Christopher Ingold Building, 20 Gordon Street , WC1H 0AJ , London , UK .
| | - Christopher A Howard
- Department of Physics & Astronomy and London Centre for Nanotechnology , University College London , Gower Street , London WC1E 6BT , UK .
| | - Paul F McMillan
- Department of Chemistry , University College London , Christopher Ingold Building, 20 Gordon Street , WC1H 0AJ , London , UK .
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Jia J, White ER, Clancy AJ, Rubio N, Suter T, Miller TS, McColl K, McMillan PF, Brázdová V, Corà F, Howard CA, Law RV, Mattevi C, Shaffer MSP. Fast Exfoliation and Functionalisation of Two-Dimensional Crystalline Carbon Nitride by Framework Charging. Angew Chem Int Ed Engl 2018; 57:12656-12660. [DOI: 10.1002/anie.201800875] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 07/13/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Jingjing Jia
- Dept. Chemistry; Imperial College London; London SW7 2AZ UK
- Current address: Dept. Materials; University of Science and Technology Beijing; Beijing 100083 China
| | | | - Adam J. Clancy
- Dept. Chemistry; Imperial College London; London SW7 2AZ UK
| | - Noelia Rubio
- Dept. Chemistry; Imperial College London; London SW7 2AZ UK
| | - Theo Suter
- Dept. Chemistry; University College London; London WC1H 0AJ UK
| | | | - Kit McColl
- Dept. Chemistry; University College London; London WC1H 0AJ UK
| | | | | | - Furio Corà
- Dept. Chemistry; University College London; London WC1H 0AJ UK
| | | | - Robert V. Law
- Dept. Chemistry; Imperial College London; London SW7 2AZ UK
| | | | - Milo S. P. Shaffer
- Dept. Chemistry; Imperial College London; London SW7 2AZ UK
- Dept. Materials; Imperial College London; London SW7 2AZ UK
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25
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Jia J, White ER, Clancy AJ, Rubio N, Suter T, Miller TS, McColl K, McMillan PF, Brázdová V, Corà F, Howard CA, Law RV, Mattevi C, Shaffer MSP. Fast Exfoliation and Functionalisation of Two-Dimensional Crystalline Carbon Nitride by Framework Charging. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800875] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jingjing Jia
- Dept. Chemistry; Imperial College London; London SW7 2AZ UK
- Current address: Dept. Materials; University of Science and Technology Beijing; Beijing 100083 China
| | | | - Adam J. Clancy
- Dept. Chemistry; Imperial College London; London SW7 2AZ UK
| | - Noelia Rubio
- Dept. Chemistry; Imperial College London; London SW7 2AZ UK
| | - Theo Suter
- Dept. Chemistry; University College London; London WC1H 0AJ UK
| | | | - Kit McColl
- Dept. Chemistry; University College London; London WC1H 0AJ UK
| | | | | | - Furio Corà
- Dept. Chemistry; University College London; London WC1H 0AJ UK
| | | | - Robert V. Law
- Dept. Chemistry; Imperial College London; London SW7 2AZ UK
| | | | - Milo S. P. Shaffer
- Dept. Chemistry; Imperial College London; London SW7 2AZ UK
- Dept. Materials; Imperial College London; London SW7 2AZ UK
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26
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Miller TS, Suter TM, Telford AM, Picco L, Payton OD, Russell-Pavier F, Cullen PL, Sella A, Shaffer MSP, Nelson J, Tileli V, McMillan PF, Howard CA. Single Crystal, Luminescent Carbon Nitride Nanosheets Formed by Spontaneous Dissolution. Nano Lett 2017; 17:5891-5896. [PMID: 28678518 DOI: 10.1021/acs.nanolett.7b01353] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A primary method for the production of 2D nanosheets is liquid-phase delamination from their 3D layered bulk analogues. Most strategies currently achieve this objective by significant mechanical energy input or chemical modification but these processes are detrimental to the structure and properties of the resulting 2D nanomaterials. Bulk poly(triazine imide) (PTI)-based carbon nitrides are layered materials with a high degree of crystalline order. Here, we demonstrate that these semiconductors are spontaneously soluble in select polar aprotic solvents, that is, without any chemical or physical intervention. In contrast to more aggressive exfoliation strategies, this thermodynamically driven dissolution process perfectly maintains the crystallographic form of the starting material, yielding solutions of defect-free, hexagonal 2D nanosheets with a well-defined size distribution. This pristine nanosheet structure results in narrow, excitation-wavelength-independent photoluminescence emission spectra. Furthermore, by controlling the aggregation state of the nanosheets, we demonstrate that the emission wavelengths can be tuned from narrow UV to broad-band white. This has potential applicability to a range of optoelectronic devices.
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Affiliation(s)
- Thomas S Miller
- Department of Chemistry, Christopher Ingold Laboratory, University College London , 20 Gordon Street, London WC1H OAJ, United Kingdom
| | - Theo M Suter
- Department of Chemistry, Christopher Ingold Laboratory, University College London , 20 Gordon Street, London WC1H OAJ, United Kingdom
| | - Andrew M Telford
- Department of Physics and Centre for Plastic Electronics, Imperial College London , London SW7 2BW, United Kingdom
| | - Loren Picco
- Interface Analysis Centre, H. H. Wills Physics Laboratory, University of Bristol , Tyndall Avenue, Bristol BS8 1TL, United Kingdom
| | - Oliver D Payton
- Interface Analysis Centre, H. H. Wills Physics Laboratory, University of Bristol , Tyndall Avenue, Bristol BS8 1TL, United Kingdom
| | - Freddie Russell-Pavier
- Interface Analysis Centre, H. H. Wills Physics Laboratory, University of Bristol , Tyndall Avenue, Bristol BS8 1TL, United Kingdom
| | - Patrick L Cullen
- Department of Physics & Astronomy, University College London , London WC1E 6BT, United Kingdom
| | - Andrea Sella
- Department of Chemistry, Christopher Ingold Laboratory, University College London , 20 Gordon Street, London WC1H OAJ, United Kingdom
| | - Milo S P Shaffer
- Department of Chemistry, Imperial College London , Exhibition Road, London SW7 2AZ, United Kingdom
| | - Jenny Nelson
- Department of Physics and Centre for Plastic Electronics, Imperial College London , London SW7 2BW, United Kingdom
| | - Vasiliki Tileli
- # Institute of Materials, École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
| | - Paul F McMillan
- Department of Chemistry, Christopher Ingold Laboratory, University College London , 20 Gordon Street, London WC1H OAJ, United Kingdom
| | - Christopher A Howard
- Department of Physics & Astronomy, University College London , London WC1E 6BT, United Kingdom
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27
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Affiliation(s)
- Thomas S. Miller
- Department of Chemistry; Christopher Ingold Building; University College London; 20 Gordon Street WC1H 0AJ London UK
- Department of Chemical Engineering; Christopher Ingold Building; University College London; Torrington Place WC1E 7JE London UK
| | - Anita d'Aleo
- Department of Chemistry; Christopher Ingold Building; University College London; 20 Gordon Street WC1H 0AJ London UK
| | - Theo Suter
- Department of Chemistry; Christopher Ingold Building; University College London; 20 Gordon Street WC1H 0AJ London UK
| | - Abil E. Aliev
- Department of Chemistry; Christopher Ingold Building; University College London; 20 Gordon Street WC1H 0AJ London UK
| | - Andrea Sella
- Department of Chemistry; Christopher Ingold Building; University College London; 20 Gordon Street WC1H 0AJ London UK
| | - Paul F. McMillan
- Department of Chemistry; Christopher Ingold Building; University College London; 20 Gordon Street WC1H 0AJ London UK
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28
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Zhang G, Güell AG, Kirkman PM, Lazenby RA, Miller TS, Unwin PR. Versatile Polymer-Free Graphene Transfer Method and Applications. ACS Appl Mater Interfaces 2016; 8:8008-16. [PMID: 26953499 DOI: 10.1021/acsami.6b00681] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A new method for transferring chemical vapor deposition (CVD)-grown monolayer graphene to a variety of substrates is described. The method makes use of an organic/aqueous biphasic configuration, avoiding the use of any polymeric materials that can cause severe contamination problems. The graphene-coated copper foil sample (on which graphene was grown) sits at the interface between hexane and an aqueous etching solution of ammonium persulfate to remove the copper. With the aid of an Si/SiO2 substrate, the graphene layer is then transferred to a second hexane/water interface to remove etching products. From this new location, CVD graphene is readily transferred to arbitrary substrates, including three-dimensional architectures as represented by atomic force microscopy (AFM) tips and transmission electron microscopy (TEM) grids. Graphene produces a conformal layer on AFM tips, to the very end, allowing easy production of tips for conductive AFM imaging. Graphene transferred to copper TEM grids provides large-area, highly electron-transparent substrates for TEM imaging. These substrates can also be used as working electrodes for electrochemistry and high-resolution wetting studies. By using scanning electrochemical cell microscopy, it is possible to make electrochemical and wetting measurements at either a freestanding graphene film or a copper-supported graphene area and readily determine any differences in behavior.
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Affiliation(s)
- Guohui Zhang
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
| | - Aleix G Güell
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
| | - Paul M Kirkman
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
| | - Robert A Lazenby
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
| | - Thomas S Miller
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
| | - Patrick R Unwin
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
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29
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Miller TS, Jorge AB, Sella A, Corà F, Shearing PR, Brett DJL, McMillan PF. The Use of Graphitic Carbon Nitride Based Composite Anodes for Lithium-Ion Battery Applications. ELECTROANAL 2015. [DOI: 10.1002/elan.201500205] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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30
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Miller TS, Macpherson JV, Unwin PR. Electrochemical activation of pristine single walled carbon nanotubes: impact on oxygen reduction and other surface sensitive redox processes. Phys Chem Chem Phys 2015; 16:9966-73. [PMID: 24472842 DOI: 10.1039/c3cp53717j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The effect of systematic anodic pre-treatments of pristine single walled carbon nanotube (SWNT) forests on the electrochemical response towards a variety of redox processes is investigated. An experimental arrangement is adopted whereby a microcapillary containing the solution of interest and a quasi reference-counter electrode is brought into contact with a small portion of the forest to enable measurements on the surface before and after controlled anodic polarisation (AP). AP of the surface is found to both improve the voltammetric response (faster apparent heterogeneous electron transfer kinetics) of surface sensitive redox processes, such as Fe(2+/3+), and enhance the electrocatalytic response of the SWNTs towards oxygen reduction; the extent of which can be carefully controlled via the applied anodic potential. AP is expected to remove any trace organic (atmospheric) contaminants that may accumulate on the forest over extended periods as well as allowing the controlled introduction of defects, as confirmed by micro-Raman spectroscopy.
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Affiliation(s)
- Thomas S Miller
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
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31
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Miller TS, Sansuk S, E SP, Lai SC, Macpherson JV, Unwin PR. Pt nanoparticle modified single walled carbon nanotube network electrodes for electrocatalysis: Control of the specific surface area over three orders of magnitude. Catal Today 2015. [DOI: 10.1016/j.cattod.2014.06.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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32
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E SP, Miller TS, Macpherson JV, Unwin PR. Controlled functionalisation of single-walled carbon nanotube network electrodes for the enhanced voltammetric detection of dopamine. Phys Chem Chem Phys 2015; 17:26394-402. [DOI: 10.1039/c5cp04905a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Acid functionalised SWNT network electrodes enhance the voltammetric detection of dopamine and minimise surface fouling.
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Affiliation(s)
- Sharel P. E
- Department of Chemistry
- University of Warwick
- Coventry
- UK
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Livzan MA, Lapteva IV, Miller TS. [Role of leptin and leptin resistance in non-alcoholic fatty liver disease development in persons with obesity and overweight]. Eksp Klin Gastroenterol 2014:27-33. [PMID: 25911909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
AIM To study the impact of leptin and leptinresistance on formation of non-alcoholic fatty liver disease (NAFLD) of people with obesity and overweight. METHODS 105 patients with obesity and overweight were examined, among them 19 men and 86 women, median age 58 (50-63) years. Risk factors development NAFLD, anthropometric indices, biochemical analysis of blood, abdominal ultrasonic studies, levels leptin and its soluble receptor were estimated. examined people with NAFLD were included into 2 groups: main group (patients NAFLD, n = 77) and comparison group (n = 28). RESULTS Waist volume, body mass index, blood glucose were higher in group of patients with NAFLD (p < 0.0001, p < 0.003, p < 0.00002, level) and had positive connection with the change in liver development (rs = (0.376), p < 0.00008, rs = (0.293), p < 0.002, rs = (0.417), p < 0.00001, level). Leptin has direct dependence (rs = (0.291), p < 0.027), while level of soluble receptors to leptin was of reverse dependence (rs = (-0.456), p < 0.0003) on the degree of body weight. Between these indicators in the group with obesity and overweight negative correlation of moderate strength (rs = (-0.370), p < 0.004) was revealed. There were tendencies to a higher level leptin and lower level receptor to leptin in group with NAFLD (median level leptin 29.20 (12.63-44.98) in main group against 27.49 (12.05-54.79), median receptor to leptin 18.25 (14.69-24.26) against 22.05 (14.57-32.04), respectively). However these indicators in the main group also had a negative correlation bond of moderate strength (rs = (-0.384), p < 0.007). CONCLUSION Development of NAFLD are associated with obesity and excess body weight, phenomenon of leptinresistance arises to patients with obesity and can be considered as predictor of the development and progression of NAFLD among this category of patients.
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Patel AN, Tan SY, Miller TS, Macpherson JV, Unwin PR. Comparison and Reappraisal of Carbon Electrodes for the Voltammetric Detection of Dopamine. Anal Chem 2013; 85:11755-64. [DOI: 10.1021/ac401969q] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Anisha N. Patel
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Sze-yin Tan
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Thomas S. Miller
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | | | - Patrick R. Unwin
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
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Abstract
BACKGROUND AND PURPOSE CT guidance is increasingly being used to localize the epidural space during epidural steroid injections. A common concern is that CT may be associated with significantly higher radiation doses compared with conventional fluoroscopy. The goal of this retrospective study was to determine the average dose-length product and effective dose delivered while interlaminar epidural steroid injections are performed and allow comparison with other modalities. MATERIALS AND METHODS A total of 281 patients who had undergone 345 consecutive CT-guided epidural steroid injections of the lumbar spine were evaluated for radiation exposure. The dose-length product for each scan was derived from the CT dose index volume and scan length. Effective dose was then calculated from the dose-length product and a κ coefficient of 0.015. Procedure time was calculated from the PACS time stamp on the scout image to the last CT image of the last image series. RESULTS The average dose-length product across all procedures was 89.6 ± 3.33 mGy·cm, which represents an effective dose of 1.34 ± 0.05 mSv. No complications from the procedure were observed, and average procedure time was 8 minutes. CONCLUSIONS The use of a stationary table and an intermittent scanning technique allow for short procedures and doses that are significantly lower than those of conventional diagnostic CT scans. Furthermore, because CT dose index overestimates radiation dose in stationary table procedures, the actual radiation dose may be even lower than stated here.
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Affiliation(s)
- A L Chang
- Department of Radiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
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Wakerley D, Güell AG, Hutton LA, Miller TS, Bard AJ, Macpherson JV. Boron doped diamond ultramicroelectrodes: a generic platform for sensing single nanoparticle electrocatalytic collisions. Chem Commun (Camb) 2013; 49:5657-9. [DOI: 10.1039/c3cc42915f] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [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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Kleijn SEF, Lai SCS, Miller TS, Yanson AI, Koper MTM, Unwin PR. Landing and Catalytic Characterization of Individual Nanoparticles on Electrode Surfaces. J Am Chem Soc 2012; 134:18558-61. [DOI: 10.1021/ja309220m] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Steven E. F. Kleijn
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The
Netherlands
| | - Stanley C. S. Lai
- Department
of Chemistry, University of Warwick, Coventry
CV4 7AL, United Kingdom
| | - Thomas S. Miller
- Department
of Chemistry, University of Warwick, Coventry
CV4 7AL, United Kingdom
| | - Alexei I. Yanson
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The
Netherlands
| | - Marc T. M. Koper
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The
Netherlands
| | - Patrick R. Unwin
- Department
of Chemistry, University of Warwick, Coventry
CV4 7AL, United Kingdom
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Miller TS, Fruauff K, Farinhas J, Pasquale D, Romano C, Schoenfeld AH, Brook A. Lateral decubitus positioning for cervical nerve root block using CT image guidance minimizes effective radiation dose and procedural time. AJNR Am J Neuroradiol 2012; 34:23-8. [PMID: 22743642 DOI: 10.3174/ajnr.a3158] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND AND PURPOSE Cervical steroid injections are a minimally invasive means of providing pain relief to patients with cervical radiculopathy. CT guidance offers many potential advantages. We developed a technique with the patient in the lateral position with a lateral needle trajectory to minimize the required needle depth from skin to target and a near-vertical needle trajectory. The aim of this study was to analyze the cohort for complications, procedural time, and effective radiation dose. MATERIALS AND METHODS This was a retrospective evaluation of a single-center patient cohort. PACS images from the procedures were reviewed for needle depth, procedural time, and CTDI(vol). An anatomically relevant conversion factor was used to calculate the effective dose. RESULTS One hundred sixteen cases from 110 patients were identified. The average patient age was 55 years. There were no complications. In 50% of cases, C5-6 was targeted. The average time was 6 minutes, and the average effective radiation dose, 0.51 mSv (0.21-2.56 mSv). Needle-insertion length from the skin to the target was highly correlated with a need for >3 needle repositioning adjustments and scan series (ρ = 0.52, P < .001) and increased procedural time (ρ = 0.42, P < .001). The angle of needle insertion relative to the floor was significantly correlated with an increased number of needle adjustments for depths >25 mm and a longer procedural time (ρ = 0.29, P = .01) but not for depths <25 mm. CONCLUSIONS The lateral patient position with CT guidance is safe and allows use of a short needle in a vertical trajectory. This reduces the number of needle adjustments and imaging series to provide a short procedural time with a low effective radiation dose from the procedure.
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Affiliation(s)
- T S Miller
- Department of Radiology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York 10463, USA.
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Miller TS, Ebejer N, Güell AG, Macpherson JV, Unwin PR. Electrochemistry at carbon nanotube forests: sidewalls and closed ends allow fast electron transfer. Chem Commun (Camb) 2012; 48:7435-7. [PMID: 22614748 DOI: 10.1039/c2cc32890a] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electrochemical properties of the closed ends and sidewalls of pristine carbon nanotube forests are investigated directly using a nanopipet electrochemical cell. Both are shown to promote fast electron transfer, without any activation or processing of the carbon nanotube material required, in contrast to the current model in the literature.
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Gamss RP, Slasky SE, Bello JA, Miller TS, Shinnar S. Prevalence of hippocampal malrotation in a population without seizures. AJNR Am J Neuroradiol 2009; 30:1571-3. [PMID: 19541778 DOI: 10.3174/ajnr.a1657] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Hippocampal malrotation (HIMAL) is a failure of hippocampal inversion that occurs during normal fetal development and has been seen on MR imaging examinations of people with epilepsy, but it has not been studied in patients without epilepsy. We intended to evaluate the prevalence of HIMAL in MR imaging examinations of patients without seizures to better understand the significance of HIMAL in the population with seizure. MATERIALS AND METHODS A total of 497 MR imaging examinations with thin-section imaging through the temporal lobes of patients referred for conditions other than seizures were reviewed. The examinations were performed on 1.5T magnets. Sagittal T1-weighted and coronal T2-weighted images were used to evaluate each MR image for the distinctive features of HIMAL. As previously described in the literature, the criteria for HIMAL include unilateral involvement and incomplete rotation of a hippocampus that is normal in size and signal intensity but abnormally rounded in shape, with blurred inner structure. In addition, ipsilateral findings of an atypical collateral sulcus angle and atypical position and size of the fornix were noted. The corpus callosum is normal, and the temporal lobe remains normal in size, though the temporal horn may appear enlarged. RESULTS None of the patients' examinations fulfilled all of the HIMAL criteria. Six studies satisfied 2 or more criteria, which included an abnormally rounded hippocampus and a vertical collateral sulcus. These HIMAL findings were all seen on the left. Forniceal asymmetry was the most prevalent abnormality, with 289 patients manifesting a low position of 1 fornix. CONCLUSIONS Hippocampal malrotation is a rare finding in patients without seizures. HIMAL is therefore likely to be a pathologic finding.
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Affiliation(s)
- R P Gamss
- Department of Radiology, Montefiore Medical Center, 111 E. 210th St., Bronx, NY 10467, USA
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Abstract
An important feature of ligand-gated ion channels is their exquisite ability to discriminate between ions. Still, little is known about the mechanisms underlying, or structural determinates of, this ability. We examined the structural elements underlying the ionic selectivity of rho1 GABA receptors expressed in Xenopus oocytes and human embryonic kidney cells using site-directed mutagenesis and two-electrode voltage-clamp or patch-clamp techniques. The wild-type GABA receptor was chloride selective, with a small but significant permeability to potassium (PNa+ : PK+ : PCl- = 0 : 0.03 :1). Mutation of an alanine to glutamate at position 291 (thought to be located at the intracellular end of the second transmembrane domain), formed a channel that exhibited little discrimination among ions (0.70:0.87:1), while deletion of a neighbouring proline (290) was chloride selective, but had elevated cation permeabilities compared to the wild-type channel (0.12 : 0.14 : 1). Together, the two mutations (DeltaP290/A291E) caused a reversal of selectivity (2.72 : 3.59 : 1). We also examined the effects of neutralizing and reversing the charge of the adjacent, and highly conserved, arginine. Mutation of the neighbouring arginine to glutamate (R292E) increased the cation permeability similar to the DeltaP290/A291E double mutant (2.4 : 3.0 : 1), whereas neutral mutations at this position (R292M or R292C) retained chloride selectivity (0 : 0.11 : 1.0 and 0 : 0.14 : 1.0, respectively). Our experiments suggest that the effective charge near the presumed intracellular mouth of the pore is critical for ionic selectivity.
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Affiliation(s)
- V E Wotring
- Department of Neurobiology, University of Alabama at Birmingham, 35294, USA
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Miller TS. From illness comes strength. A nursing student with Crohn's disease tells her story. Imprint 2001; 48:45, 75. [PMID: 12152539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Affiliation(s)
- T S Miller
- Georgetown University School of Nursing and Health Studies, Washington, DC, USA
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Boudreaux GM, Miller TS, Kunefke AJ, Singh JP, Yueh FY, Monts DL. Development of a photofragmentation laser-induced-fluorescence laser sensor for detection of 2, 4, 6-trinitrotoluene in soil and groundwater. Appl Opt 1999; 38:1411-1417. [PMID: 18305761 DOI: 10.1364/ao.38.001411] [Citation(s) in RCA: 6] [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: 05/26/2023]
Abstract
Laser photofragmentation (PF) and subsequent nitric oxide (NO) laser-induced fluorescence (LIF) have been developed to measure the concentration of energetic materials (EM's), such as 2, 4, 6-trinitrotoluene (TNT), in soil and other media. Gas-phase EM's photodissociate, releasing NO(2), when exposed to laser radiation near 226 nm. Laser-excited NO(2) predissociates to form NO that gives an intense fluorescence when excited near 226 nm. The EM concentration is inferred from the intensity of the NO fluorescence. A PF-LIF laser-based sensor is being developed to be used with the U.S. Army Corps of Engineers' Waterways Experiment Station's cone penetrometer to measure in situ the concentration of subsurface TNT. Several factors that affect the PF-LIF signal waveforms, such as sample temperature, laser power, and heating time, were investigated. Also, effects on the PF-LIF signal of adding water and fertilizer to the TNT mixtures were studied. Decay times were determined by least-squares fitting of the exponential PF-LIF signal waveforms. The use of PF-LIF waveforms promises to enable diagnostics of the sample's characteristics that would otherwise not be possible in situ.
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Affiliation(s)
- G M Boudreaux
- Department of Physics and Astronomy and the Diagnostic Instrumentation and Analysis Laboratory, Mississippi State University, Mississippi State, Mississippi 39762-5932, USA
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Miller TS. Byzantine physicians and their hospitals. Med Secoli 1999; 11:323-35. [PMID: 11624568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
Abstract
Byzantine medicine was organized around hospitals. By the eleventh and twelfth centuries, the best physicians of Constantinople treated their patients either in hospitals or in walk-in dispensaries which formed part of the hospital facilities. Byzantine hospitals were thus medical institutions. This article will review the evidence for this conclusion and introduce two new texts dealing with hospitals in Constantinople. The article will close by suggesting avenues for future research, especially regarding hospitals in provincial cities.
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Affiliation(s)
- T S Miller
- Department of History, Salisbury State University, MD, USA
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Frankenthaler RA, el-Naggar AK, Ordonez NG, Miller TS, Batsakis JG. High correlation with survival of proliferating cell nuclear antigen expression in mucoepidermoid carcinoma of the parotid gland. Otolaryngol Head Neck Surg 1994; 111:460-6. [PMID: 7936679 DOI: 10.1177/019459989411100412] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We tested the hypothesis that proliferating cell nuclear antigen can predict survival in patients with mucoepidermoid carcinoma. Formalin-fixed, paraffin-embedded, tissue resected specimens from 43 patients with no prior treatment for mucoepidermoid carcinoma of the parotid gland were immunostained with the PC10 monoclonal antibody to proliferating cell nuclear antigen with the peroxidase/antiperoxidase method. Proliferating cell nuclear antigen levels were defined as the number of nuclei with strong immunostaining divided by the total cell count and were expressed as percentages. Both univariate and multivariate analyses were performed on 12 additional prognostic variables to determine the relative proliferating cell nuclear antigen level to predict survival. The median proliferating cell nuclear antigen level was 7. Five percent of patients with proliferating cell nuclear antigen levels less than 7 died of their disease compared with 48% of those with proliferating cell nuclear antigen levels of 7 or more. Multivariate analysis indicates proliferating cell nuclear antigen to be the most important parameter in predicting survival. Thus the measurement of proliferating cell nuclear antigen is a useful predictor of survival for patients with mucoepidermoid carcinoma of the parotid gland.
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Affiliation(s)
- R A Frankenthaler
- Department of Head and Neck Surgery, University of Texas M. D. Anderson Cancer Center, Houston
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Miller TS. The plague in John VI Cantacuzenus and Thucydides. Greek Roman Byz Stud (Cambridge Mass) 1976; 17:385-395. [PMID: 11636765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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