1
|
Schoske L, Lübkemann-Warwas F, Morales I, Wesemann C, Eckert JG, Graf RT, Bigall NC. Magnetic aerogels from FePt and CoPt 3 directly from organic solution. NANOSCALE 2024; 16:4229-4238. [PMID: 38345355 DOI: 10.1039/d3nr05892a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Here the synthesis of magnetic aerogels from iron platinum and cobalt platinum nanoparticles is presented. The use of hydrazine monohydrate as destabilizing agent triggers the gelation directly from organic solution, and therefore a phase transfer to aqueous media prior to the gelation is not necessary. The aerogels were characterized through Transmission Electron Microscopy, Scanning Electron Microscopy, Powder X-Ray Diffraction Analysis and Argon Physisorption measurements to prove the formation of a porous network and define their compositions. Additionally, magnetization measurements in terms of hysteresis cycles at 5 K and 300 K (M-H-curves) as well as zero field cooled-field cooled measurements (ZFC-FC measurements) of the dried colloids and the respective xero- and aerogels were performed, in order to analyze the influence of the gelation process and the network structure on the magnetic properties.
Collapse
Affiliation(s)
- L Schoske
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover, Germany.
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering- Innovation Across Disciplines), Leibniz University Hannover, 30167 Hannover, Germany
- Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Hamburg, Germany
| | - F Lübkemann-Warwas
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover, Germany.
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering- Innovation Across Disciplines), Leibniz University Hannover, 30167 Hannover, Germany
| | - I Morales
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover, Germany.
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering- Innovation Across Disciplines), Leibniz University Hannover, 30167 Hannover, Germany
| | - C Wesemann
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover, Germany.
| | - J G Eckert
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover, Germany.
- School of Additive Manufacturing, Ministry for Science and Culture of Lower Saxony, Hannover, Germany
| | - R T Graf
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover, Germany.
- Laboratory of Nano and Quantum Engineering, Leibniz University Hannover, Schneiderberg 39, 30167 Hannover, Germany
| | - N C Bigall
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover, Germany.
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering- Innovation Across Disciplines), Leibniz University Hannover, 30167 Hannover, Germany
- School of Additive Manufacturing, Ministry for Science and Culture of Lower Saxony, Hannover, Germany
- Laboratory of Nano and Quantum Engineering, Leibniz University Hannover, Schneiderberg 39, 30167 Hannover, Germany
- Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Hamburg, Germany
| |
Collapse
|
2
|
Pluta D, Kuper H, Graf RT, Wesemann C, Rusch P, Becker JA, Bigall NC. Optical properties of NIR photoluminescent PbS nanocrystal-based three-dimensional networks. NANOSCALE ADVANCES 2023; 5:5005-5014. [PMID: 37705785 PMCID: PMC10496766 DOI: 10.1039/d3na00404j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/25/2023] [Indexed: 09/15/2023]
Abstract
The assembly of nanocrystals (NCs) into three-dimensional network structures is a recently established strategy to produce macroscopic materials with nanoscopic properties. These networks can be formed by the controlled destabilization of NC colloids and subsequent supercritical drying to obtain NC-based aerogels. Even though this strategy has been used for many different semiconductor NCs, the emission of NC-based aerogels is limited to the ultraviolet and visible and no near-infrared (NIR) emitting NC-based aerogels have been investigated in literature until now. In the present work we have optimized a gelation route of NIR emitting PbS and PbS/CdS quantum dots (QDs) by means of a recently established gel formation method using trivalent ions to induce the network formation. Thereby, depending on the surface ligands and QDs used the resulting network structure is different. We propose, that the ligand affinity to the nanocrystal surface plays an essential role during network formation, which is supported by theoretical calculations. The optical properties were investigated with a focus on their steady-state and time resolved photoluminescence (PL). Unlike in PbS/CdS aerogels, the absorption of PbS aerogels and their PL shift strongly. For all aerogels the PL lifetimes are reduced in comparison to those of the building blocks with this reduction being especially pronounced in the PbS aerogels.
Collapse
Affiliation(s)
- Denis Pluta
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
- Laboratory of Nano and Quantum Engineering, Leibniz University Hannover Schneiderberg 39 30167 Hannover Germany
| | - Henning Kuper
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
| | - Rebecca T Graf
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
- Laboratory of Nano and Quantum Engineering, Leibniz University Hannover Schneiderberg 39 30167 Hannover Germany
| | - Christoph Wesemann
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
| | - Pascal Rusch
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
- Laboratory of Nano and Quantum Engineering, Leibniz University Hannover Schneiderberg 39 30167 Hannover Germany
| | - Joerg August Becker
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
| | - Nadja C Bigall
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
- Laboratory of Nano and Quantum Engineering, Leibniz University Hannover Schneiderberg 39 30167 Hannover Germany
| |
Collapse
|
3
|
Kang J, Sherman ZM, Crory HSN, Conrad DL, Berry MW, Roman BJ, Anslyn EV, Truskett TM, Milliron DJ. Modular mixing in plasmonic metal oxide nanocrystal gels with thermoreversible links. J Chem Phys 2023; 158:024903. [PMID: 36641404 DOI: 10.1063/5.0130817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Gelation offers a powerful strategy to assemble plasmonic nanocrystal networks incorporating both the distinctive optical properties of constituent building blocks and customizable collective properties. Beyond what a single-component assembly can offer, the characteristics of nanocrystal networks can be tuned in a broader range when two or more components are intimately combined. Here, we demonstrate mixed nanocrystal gel networks using thermoresponsive metal-terpyridine links that enable rapid gel assembly and disassembly with thermal cycling. Plasmonic indium oxide nanocrystals with different sizes, doping concentrations, and shapes are reliably intermixed in linked gel assemblies, exhibiting collective infrared absorption that reflects the contributions of each component while also deviating systematically from a linear combination of the spectra for single-component gels. We extend a many-bodied, mutual polarization method to simulate the optical response of mixed nanocrystal gels, reproducing the experimental trends with no free parameters and revealing that spectral deviations originate from cross-coupling between nanocrystals with distinct plasmonic properties. Our thermoreversible linking strategy directs the assembly of mixed nanocrystal gels with continuously tunable far- and near-field optical properties that are distinct from those of the building blocks or mixed close-packed structures.
Collapse
Affiliation(s)
- Jiho Kang
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| | - Zachary M Sherman
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| | - Hannah S N Crory
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Diana L Conrad
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Marina W Berry
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Benjamin J Roman
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| | - Eric V Anslyn
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Thomas M Truskett
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| | - Delia J Milliron
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| |
Collapse
|
4
|
Rusch P, Lübkemann F, Borg H, Eckert JG, Dorfs D, Bigall NC. Influencing the coupling between network building blocks in CdSe/CdS dot/rod aerogels by partial cation exchange. J Chem Phys 2022; 156:234701. [PMID: 35732518 DOI: 10.1063/5.0093761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The assembly of CdSe/CdS dot/rod nanocrystals (NCs) with variable length of ZnS tips into aerogel networks is presented. To this end, a partial region selective cation exchange procedure is performed replacing Cd by Zn starting at the NC tip. The produced aerogel networks are investigated structurally and optically. The networks of tip-to-tip connected NCs have an intricate band structure with holes confined to the CdSe cores while electrons are delocalized within the CdS also within connected building blocks. However, the ZnS tips act as a barrier of variable length and strength between the NC building blocks partly confining the electrons. This results in NC based aerogel networks with tunable strength of coupling between building blocks.
Collapse
Affiliation(s)
- Pascal Rusch
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
| | - Franziska Lübkemann
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
| | - Hadir Borg
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
| | - J Gerrit Eckert
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
| | - Dirk Dorfs
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
| | - Nadja C Bigall
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
| |
Collapse
|