1
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Sherman Z, Kang J, Milliron DJ, Truskett TM. Illuminating Disorder: Optical Properties of Complex Plasmonic Assemblies. J Phys Chem Lett 2024; 15:6424-6434. [PMID: 38864822 PMCID: PMC11194822 DOI: 10.1021/acs.jpclett.4c01283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/04/2024] [Accepted: 06/05/2024] [Indexed: 06/13/2024]
Abstract
The optical properties of disordered plasmonic nanoparticle assemblies can be continuously tuned through the structural organization and composition of their colloidal building blocks. However, progress in the design and experimental realization of these materials has been limited by challenges associated with controlling and characterizing disordered assemblies and predicting their optical properties. This Perspective discusses integrated studies of experimental assembly of disordered optical materials, such as doped metal oxide nanocrystal gels and metasurfaces, with electromagnetic computations on large-scale simulated structures. The simulations prove vital for connecting experimental parameters to disordered structural motifs and optical properties, revealing structure-property relations that inform design choices. Opportunities are identified for optimizing optical property designs for disordered materials using computational inverse methods and tools from machine learning.
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Affiliation(s)
- Zachary
M. Sherman
- Department
of Chemical Engineering, University of Washington, 3781 Okanogan Lane, Seattle, Washington 98195, United States
- McKetta
Department of Chemical Engineering, University
of Texas at Austin, 200 E Dean Keeton Street, Austin, Texas 78712, United States
| | - Jiho Kang
- McKetta
Department of Chemical Engineering, University
of Texas at Austin, 200 E Dean Keeton Street, Austin, Texas 78712, United States
| | - Delia J. Milliron
- McKetta
Department of Chemical Engineering, University
of Texas at Austin, 200 E Dean Keeton Street, Austin, Texas 78712, United States
- Department
of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, Texas 78712, United States
| | - Thomas M. Truskett
- McKetta
Department of Chemical Engineering, University
of Texas at Austin, 200 E Dean Keeton Street, Austin, Texas 78712, United States
- Department
of Physics, University of Texas at Austin, 2515 Speedway, Austin, Texas 78712, United States
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2
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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.
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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
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3
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Li G, Chen Y, Liu F, Bi W, Wang C, Lu D, Wen D. Portable visual and electrochemical detection of hydrogen peroxide release from living cells based on dual-functional Pt-Ni hydrogels. MICROSYSTEMS & NANOENGINEERING 2023; 9:152. [PMID: 38033990 PMCID: PMC10684573 DOI: 10.1038/s41378-023-00623-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/20/2023] [Accepted: 10/10/2023] [Indexed: 12/02/2023]
Abstract
It is important to monitor the intra-/extracellular concentration of hydrogen peroxide (H2O2) in biological processes. However, miniaturized devices that enable portable and accurate H2O2 measurement are still in their infancy because of the difficulty of developing facile sensing strategies and highly integrated sensing devices. In this work, portable H2O2 sensors based on Pt-Ni hydrogels with excellent peroxidase-like and electrocatalytic activities are demonstrated. Thus, simple and sensitive H2O2 sensing is achieved through both colorimetric and electrochemical strategies. The as-fabricated H2O2 sensing chips exhibit favorable performance, with low detection limits (0.030 μM & 0.15 μM), wide linearity ranges (0.10 μM-10.0 mM & 0.50 μM-5.0 mM), outstanding long-term stability (up to 60 days), and excellent selectivity. With the aid of an M5stack development board, portable visual and electrochemical H2O2 sensors are successfully constructed without complicated and expensive equipment or professional operators. When applied to the detection of H2O2 released from HeLa cells, the results obtained by the developed sensors are in good agreement with those from an ultraviolet‒visible spectrophotometer (UV‒vis) (1.97 μM vs. 2.08 μM) and electrochemical station (1.77 μM vs. 1.84 μM).
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Affiliation(s)
- Guanglei Li
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi’an, 710072 P. R. China
- Interdisciplinary Research Center of Biology & Catalysis, School of Life Sciences, NPU, Xi’an, 710072 P. R. China
| | - Yao Chen
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi’an, 710072 P. R. China
| | - Fei Liu
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi’an, 710072 P. R. China
| | - Wenhua Bi
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi’an, 710072 P. R. China
| | - Chenxin Wang
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi’an, 710072 P. R. China
| | - Danfeng Lu
- Faculty of Printing, Packaging Engineering, and Digital Media Technology, Xi’an University of Technology, Xi’an, 710048 P. R. China
| | - Dan Wen
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi’an, 710072 P. R. China
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4
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Kang J, Sherman ZM, Conrad DL, Crory HSN, Dominguez MN, Valenzuela SA, Anslyn EV, Truskett TM, Milliron DJ. Structural Control of Plasmon Resonance in Molecularly Linked Metal Oxide Nanocrystal Gel Assemblies. ACS NANO 2023. [PMID: 38009590 DOI: 10.1021/acsnano.3c09515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Nanocrystal gels exhibit collective optical phenomena based on interactions among their constituent building blocks. However, their inherently disordered structures have made it challenging to understand, predict, or design properties such as optical absorption spectra that are sensitive to the coupling between the plasmon resonances of the individual nanocrystals. Here, we bring indium tin oxide nanocrystal gels under chemical control and show that their infrared absorption can be predicted and systematically tuned by selecting the nanocrystal sizes and compositions and molecular structures of the link-mediating surface ligands. Thermoreversible assemblies with metal-terpyridine links form reproducible gel architectures, enabling us to derive a plasmon ruler that governs the spectral shifts upon gelation, predicated on the nanocrystal and ligand compositions. This empirical guide is validated using large-scale, many-bodied simulations to compute the optical spectra of gels with varied structural parameters. Based on the derived plasmon ruler, we design and demonstrate a nanocrystal mixture whose spectrum exhibits distinctive line narrowing upon assembly.
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Affiliation(s)
- Jiho Kang
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton St., Austin, Texas 78712, United States
| | - Zachary M Sherman
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton St., Austin, Texas 78712, United States
| | - Diana L Conrad
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, Texas 78712, United States
| | - Hannah S N Crory
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, Texas 78712, United States
| | - Manuel N Dominguez
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, Texas 78712, United States
| | - Stephanie A Valenzuela
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, Texas 78712, United States
| | - Eric V Anslyn
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, Texas 78712, United States
| | - Thomas M Truskett
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton St., Austin, Texas 78712, United States
- Department of Physics, University of Texas at Austin, 2515 Speedway, Austin, Texas 78712, United States
| | - Delia J Milliron
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton St., Austin, Texas 78712, United States
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, Texas 78712, United States
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5
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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.
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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
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6
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Schlenkrich J, Lübkemann-Warwas F, Graf RT, Wesemann C, Schoske L, Rosebrock M, Hindricks KDJ, Behrens P, Bahnemann DW, Dorfs D, Bigall NC. Investigation of the Photocatalytic Hydrogen Production of Semiconductor Nanocrystal-Based Hydrogels. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2208108. [PMID: 36828791 DOI: 10.1002/smll.202208108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/03/2023] [Indexed: 05/25/2023]
Abstract
Destabilization of a ligand-stabilized semiconductor nanocrystal solution with an oxidizing agent can lead to a macroscopic highly porous self-supporting nanocrystal network entitled hydrogel, with good accessibility to the surface. The previously reported charge carrier delocalization beyond a single nanocrystal building block in such gels can extend the charge carrier mobility and make a photocatalytic reaction more probable. The synthesis of ligand-stabilized nanocrystals with specific physicochemical properties is possible, thanks to the advances in colloid chemistry made in the last decades. Combining the properties of these nanocrystals with the advantages of nanocrystal-based hydrogels will lead to novel materials with optimized photocatalytic properties. This work demonstrates that CdSe quantum dots, CdS nanorods, and CdSe/CdS dot-in-rod-shaped nanorods as nanocrystal-based hydrogels can exhibit a much higher hydrogen production rate compared to their ligand-stabilized nanocrystal solutions. The gel synthesis through controlled destabilization by ligand oxidation preserves the high surface-to-volume ratio, ensures the accessible surface area even in hole-trapping solutions and facilitates photocatalytic hydrogen production without a co-catalyst. Especially with such self-supporting networks of nanocrystals, the problem of colloidal (in)stability in photocatalysis is circumvented. X-ray photoelectron spectroscopy and photoelectrochemical measurements reveal the advantageous properties of the 3D networks for application in photocatalytic hydrogen production.
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Affiliation(s)
- Jakob Schlenkrich
- Leibniz University Hannover, Institute of Physical Chemistry and Electrochemistry, Callinstraße 3A, 30167, Hannover, Germany
| | - Franziska Lübkemann-Warwas
- Leibniz University Hannover, Institute of Physical Chemistry and Electrochemistry, Callinstraße 3A, 30167, Hannover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering -Innovation Across Disciplines), Leibniz University Hannover, 30167, Hannover, Germany
| | - Rebecca T Graf
- Leibniz University Hannover, Institute of Physical Chemistry and Electrochemistry, Callinstraße 3A, 30167, Hannover, Germany
- Laboratory of Nano- and Quantum Engineering, Leibniz University Hannover, 30167, Hannover, Germany
| | - Christoph Wesemann
- Leibniz University Hannover, Institute of Physical Chemistry and Electrochemistry, Callinstraße 3A, 30167, Hannover, Germany
| | - Larissa Schoske
- Leibniz University Hannover, Institute of Physical Chemistry and Electrochemistry, Callinstraße 3A, 30167, Hannover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering -Innovation Across Disciplines), Leibniz University Hannover, 30167, Hannover, Germany
| | - Marina Rosebrock
- Leibniz University Hannover, Institute of Physical Chemistry and Electrochemistry, Callinstraße 3A, 30167, Hannover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering -Innovation Across Disciplines), Leibniz University Hannover, 30167, Hannover, Germany
| | - Karen D J Hindricks
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering -Innovation Across Disciplines), Leibniz University Hannover, 30167, Hannover, Germany
- Leibniz University Hannover, Institute of Inorganic Chemistry, Callinstraße 9, 30167, Hannover, Germany
| | - Peter Behrens
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering -Innovation Across Disciplines), Leibniz University Hannover, 30167, Hannover, Germany
- Laboratory of Nano- and Quantum Engineering, Leibniz University Hannover, 30167, Hannover, Germany
- Leibniz University Hannover, Institute of Inorganic Chemistry, Callinstraße 9, 30167, Hannover, Germany
| | - Detlef W Bahnemann
- Leibniz University Hannover, Institute of Technical Chemistry, Callinstraße 5, 30167, Hannover, Germany
- Laboratory "Photoactive Nanocomposite Materials", Saint-Petersburg State University, Ulyanovskaya str. 1, Saint-Petersburg, 198504, Peterhof, Russia
| | - Dirk Dorfs
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering -Innovation Across Disciplines), Leibniz University Hannover, 30167, Hannover, Germany
- Laboratory of Nano- and Quantum Engineering, Leibniz University Hannover, 30167, Hannover, Germany
| | - Nadja C Bigall
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering -Innovation Across Disciplines), Leibniz University Hannover, 30167, Hannover, Germany
- Laboratory of Nano- and Quantum Engineering, Leibniz University Hannover, 30167, Hannover, Germany
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7
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Li G, Wang C, Chen Y, Liu F, Fan H, Yao B, Hao J, Yu Y, Wen D. Dual Structural Design of Platinum-Nickel Hydrogels for Wearable Glucose Biosensing with Ultrahigh Stability. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206868. [PMID: 36710247 DOI: 10.1002/smll.202206868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 01/14/2023] [Indexed: 06/18/2023]
Abstract
Wearable glucose sensors are of great significance and highly required in mobile health monitoring and management but suffering from limited long-term stability and wearable adaptability. Here a simultaneous component and structure engineering strategy is presented, which involves Pt with abundant Ni to achieve three-dimensional, dual-structural Pt-Ni hydrogels with interconnected networks of PtNi nanowires and Ni(OH)2 nanosheets, showing prominent electrocatalytic activity and stability in glucose oxidation under neutral condition. Specifically, the PtNi(1:3) dual hydrogels shows 2.0 and 270.6 times' activity in the glucose electro-oxidation as much as the pure Pt and Ni hydrogels. Thanks to the high activity, structural stability, good flexibility, and self-healing property, the PtNi(1:3) dual gel-based non-enzymatic glucose sensing chip is endowed with high performance. It features a high sensitivity, an excellent selectivity and flexibility, and particularly an outstanding long-term stability over 2 months. Together with a pH sensor and a wireless circuit, an accurate, real-time, and remote monitoring of sweat glucose is achieved. This facile design of novel dual-structural metallic hydrogels sheds light to rationally develop new functional materials for high-performance wearable biosensors.
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Affiliation(s)
- Guanglei Li
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi'an, 710072, P. R. China
| | - Chenxin Wang
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi'an, 710072, P. R. China
| | - Yao Chen
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi'an, 710072, P. R. China
| | - Fei Liu
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi'an, 710072, P. R. China
| | - Haoxin Fan
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi'an, 710072, P. R. China
| | - Bin Yao
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi'an, 710072, P. R. China
| | - Jia Hao
- Key Laboratory of Micro/Nano Systems for Aerospace (Ministry of Education), Shaanxi Province Key Laboratory of Micro and Nano Electro-Mechanical Systems, School of Mechanical Engineering, NPU, Xi'an, 710072, P. R. China
| | - Yiting Yu
- Key Laboratory of Micro/Nano Systems for Aerospace (Ministry of Education), Shaanxi Province Key Laboratory of Micro and Nano Electro-Mechanical Systems, School of Mechanical Engineering, NPU, Xi'an, 710072, P. R. China
| | - Dan Wen
- State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University (NPU) and Shaanxi Joint Laboratory of Graphene, Xi'an, 710072, P. R. China
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8
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Rosebrock M, Zámbó D, Rusch P, Graf RT, Pluta D, Borg H, Dorfs D, Bigall NC. Morphological Control Over Gel Structures of Mixed Semiconductor-Metal Nanoparticle Gel Networks with Multivalent Cations. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206818. [PMID: 36642817 DOI: 10.1002/smll.202206818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/15/2022] [Indexed: 06/17/2023]
Abstract
In this work, the influence of two different types of cations on the gel formation and structure of mixed gel networks comprised of semiconductor (namely CdSe/CdS nanorods NR) and Au nanoparticles (NP) as well as on the respective monocomponent gels is investigated. Heteroassemblies built from colloidal building blocks are usually prepared by ligand removal or cross-linking, thus, both the surface chemistry and the destabilising agent play an essential role in the gelation process. Due to the diversity of the composition, morphology, and optical properties of the nanoparticles, a versatile route to fabricate functional heteroassemblies is of great demand. In the present work, the optics, morphology, and gelation mechanism of pure semiconductor and noble metal as well as their mixed nanoparticle gel networks are revealed. The influence of the gelation agents (bivalent and trivalent cations) on the structure-property correlation is elucidated by photoluminescence, X-ray photoelectron spectroscopy, and electron microscopy measurements. The selection of cations drastically influences the nano- and microstructure of the prepared gel network structures driven by the affinity of the cations to the ligands and the nanoparticle surface. This gelation technique provides a new platform to control the formation of porous assemblies based on semiconductor and metal nanoparticles.
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Affiliation(s)
- Marina Rosebrock
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, 30167, Hanover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines) Leibniz Universität Hannover, 30167, Hanover, Germany
| | - Dániel Zámbó
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest, 1121, Hungary
| | - Pascal Rusch
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, 30167, Hanover, Germany
| | - Rebecca T Graf
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, 30167, Hanover, Germany
- Laboratory for Nano and Quantum Engineering, Leibniz Universität Hannover, 30167, Hanover, Germany
| | - Denis Pluta
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, 30167, Hanover, Germany
- Laboratory for Nano and Quantum Engineering, Leibniz Universität Hannover, 30167, Hanover, Germany
| | - Hadir Borg
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, 30167, Hanover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines) Leibniz Universität Hannover, 30167, Hanover, Germany
| | - Dirk Dorfs
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, 30167, Hanover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines) Leibniz Universität Hannover, 30167, Hanover, Germany
- Laboratory for Nano and Quantum Engineering, Leibniz Universität Hannover, 30167, Hanover, Germany
| | - Nadja C Bigall
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, 30167, Hanover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines) Leibniz Universität Hannover, 30167, Hanover, Germany
- Laboratory for Nano and Quantum Engineering, Leibniz Universität Hannover, 30167, Hanover, Germany
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9
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Wang C, Herranz J, Hübner R, Schmidt TJ, Eychmüller A. Element Distributions in Bimetallic Aerogels. Acc Chem Res 2023; 56:237-247. [PMID: 36700845 DOI: 10.1021/acs.accounts.2c00491] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
ConspectusMetal aerogels assembled from nanoparticles have captured grand attention because they combine the virtues of metals and aerogels and are regarded as ideal materials to address current environmental and energy issues. Among these aerogels, those composed of two metals not only display combinations (superpositions) of the properties of their individual metal components but also feature novel properties distinctly different from those of their monometallic relatives. Therefore, quite some effort has been invested in refining the synthetic methods, compositions, and structures of such bimetallic aerogels as to boost their performance for the envisaged application(s). One such use would be in the field of electrocatalysis, whereby it is also of utmost interest to unravel the element distributions of the (multi)metallic catalysts to achieve a ratio of their bottom-to-up design. Regarding the element distributions in bimetallic aerogels, advanced characterization techniques have identified alloys, core-shells, and structures in which the two metal particles are segregated (i.e., adjacent but without alloy or core-shell structure formation). While an almost infinite number of metal combinations to form bimetallic aerogels can be envisaged, the knowledge of their formation mechanisms and the corresponding element distributions is still in its infancy. The evolution of the observed musters is all but well understood, not to mention the positional changes of the elements observed in operando or in beginning- vs end-of-life comparisons (e.g., in fuel cell applications).With this motivation, in this Account we summarize the endeavors made in element distribution monitoring in bimetallic aerogels in terms of synthetic methods, expected structures, and their evolution during electrocatalysis. After an introductory chapter, we first describe briefly the two most important characterization techniques used for this, namely, scanning transmission electron microscopy (STEM) combined with element mapping (e.g., energy-dispersive X-ray spectroscopy (EDXS)) and X-ray absorption spectroscopy (XAS). We then explain the universal methods used to prepare bimetallic aerogels with different compositions. Those are divided into one-step methods in which gels formed from mixtures of the respective metal salts are coreduced and two-step approaches in which monometallic nanoparticles are mixed and gelated. Subsequently, we summarize the current state-of-knowledge on the element distributions unraveled using diverse characterization methods. This is extended to investigations of the element distributions being altered during electrochemical cycling or other loads. So far, a theoretical understanding of these processes is sparse, not to mention predictions of element distributions. The Account concludes with a series of remarks on current challenges in the field and an outlook on the gains that the field would earn from a solid understanding of the underlying processes and a predictive theoretical backing.
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Affiliation(s)
- Cui Wang
- Physical Chemistry, Technische Universität Dresden, Zellescher Weg 19, 01069 Dresden, Germany
| | - Juan Herranz
- Electrochemistry Laboratory, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - René Hübner
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Thomas J Schmidt
- Electrochemistry Laboratory, Paul Scherrer Institut, 5232 Villigen, Switzerland.,Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Alexander Eychmüller
- Physical Chemistry, Technische Universität Dresden, Zellescher Weg 19, 01069 Dresden, Germany
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10
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Diroll BT, Guzelturk B, Po H, Dabard C, Fu N, Makke L, Lhuillier E, Ithurria S. 2D II-VI Semiconductor Nanoplatelets: From Material Synthesis to Optoelectronic Integration. Chem Rev 2023; 123:3543-3624. [PMID: 36724544 DOI: 10.1021/acs.chemrev.2c00436] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The field of colloidal synthesis of semiconductors emerged 40 years ago and has reached a certain level of maturity thanks to the use of nanocrystals as phosphors in commercial displays. In particular, II-VI semiconductors based on cadmium, zinc, or mercury chalcogenides can now be synthesized with tailored shapes, composition by alloying, and even as nanocrystal heterostructures. Fifteen years ago, II-VI semiconductor nanoplatelets injected new ideas into this field. Indeed, despite the emergence of other promising semiconductors such as halide perovskites or 2D transition metal dichalcogenides, colloidal II-VI semiconductor nanoplatelets remain among the narrowest room-temperature emitters that can be synthesized over a wide spectral range, and they exhibit good material stability over time. Such nanoplatelets are scientifically and technologically interesting because they exhibit optical features and production advantages at the intersection of those expected from colloidal quantum dots and epitaxial quantum wells. In organic solvents, gram-scale syntheses can produce nanoparticles with the same thicknesses and optical properties without inhomogeneous broadening. In such nanoplatelets, quantum confinement is limited to one dimension, defined at the atomic scale, which allows them to be treated as quantum wells. In this review, we discuss the synthetic developments, spectroscopic properties, and applications of such nanoplatelets. Covering growth mechanisms, we explain how a thorough understanding of nanoplatelet growth has enabled the development of nanoplatelets and heterostructured nanoplatelets with multiple emission colors, spatially localized excitations, narrow emission, and high quantum yields over a wide spectral range. Moreover, nanoplatelets, with their large lateral extension and their thin short axis and low dielectric surroundings, can support one or several electron-hole pairs with large exciton binding energies. Thus, we also discuss how the relaxation processes and lifetime of the carriers and excitons are modified in nanoplatelets compared to both spherical quantum dots and epitaxial quantum wells. Finally, we explore how nanoplatelets, with their strong and narrow emission, can be considered as ideal candidates for pure-color light emitting diodes (LEDs), strong gain media for lasers, or for use in luminescent light concentrators.
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Affiliation(s)
- Benjamin T Diroll
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - Burak Guzelturk
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - Hong Po
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Corentin Dabard
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Ningyuan Fu
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Lina Makke
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Emmanuel Lhuillier
- Sorbonne Université, CNRS, Institut des NanoSciences de Paris, INSP, 75005 Paris, France
| | - Sandrine Ithurria
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
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11
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Gao X, Jiang G, Gao C, Prudnikau A, Hübner R, Zhan J, Zou G, Eychmüller A, Cai B. Interparticle Charge-Transport-Enhanced Electrochemiluminescence of Quantum-Dot Aerogels. Angew Chem Int Ed Engl 2023; 62:e202214487. [PMID: 36347831 DOI: 10.1002/anie.202214487] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Indexed: 11/11/2022]
Abstract
Electrochemiluminescence (ECL) represents a widely explored technique to generate light, in which the emission intensity relies critically on the charge-transfer reactions between electrogenerated radicals. Two types of charge-transfer mechanisms have been postulated for ECL generation, but the manipulation and effective probing of these routes remain a fundamental challenge. Here, we demonstrate the design of quantum dot (QD) aerogels as novel ECL luminophores via a versatile water-induced gelation strategy. The strong electronic coupling between adjacent QDs enables efficient charge transport within the aerogel network, leading to the generation of highly efficient ECL based on the selectively improved interparticle charge-transfer route. This mechanism is further verified by designing CdSe-CdTe mixed QD aerogels, where the two mechanistic routes are clearly decoupled for ECL generation. We anticipate our work will advance the fundamental understanding of ECL and prove useful for designing next-generation QD-based devices.
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Affiliation(s)
- Xuwen Gao
- School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, China
| | - Guocan Jiang
- Physical Chemistry, Technische Universität Dresden, 01069, Dresden, Germany
| | - Cunyuan Gao
- School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, China
| | - Anatol Prudnikau
- Physical Chemistry, Technische Universität Dresden, 01069, Dresden, Germany
| | - René Hübner
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Jinhua Zhan
- School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, China
| | - Guizheng Zou
- School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, China
| | | | - Bin Cai
- School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, China
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12
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Meng Y, Wang Y, Ye Z, Wang N, He C, Zhu Y, Fujita T, Wu H, Wang X. Three-dimension titanium phosphate aerogel for selective removal of radioactive strontium(II) from contaminated waters. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 325:116424. [PMID: 36283167 DOI: 10.1016/j.jenvman.2022.116424] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/20/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
The effective removal of radioactive strontium (especially 90Sr) from nuclear wastewater is crucial to environmental safety. Nevertheless, materials with excellent selectivity in Sr removal remain a challenge since the similarity with alkaline earth metal ions in the liquid phase. In this work, a novel titanium phosphate (TiP) aerogel was investigated for Sr(II) removal from the radioactive wastewater based on the sol-gel method and supercritical drying technique. The TiP aerogel has amorphous, three-dimensional and mesoporous structures with abundant phosphate groups, which was confirmed by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), atomic force microscope (AFM) and Fourier transform infrared spectroscopy (FT-IR). The adsorbent exhibited high efficiency and selectivity for the removal of Sr(II) with an extensive distribution coefficient up to 4740.03 mL/g. The adsorption equilibrium reached within 10 min and the maximum adsorption capacity was 373.6 mg/g at pH 5. And the kinetics and thermodynamics data fitted well with the pseudo-second-order model and Langmuir model respectively. It can be attributed to the rapid trapping and slow intraparticle diffusion of Sr(II) inside the mesoporous channels of the TiP aerogel. Furthermore, TiP aerogel exhibited over 80% removal for 50 mg/L Sr2+ in real water systems (seawater, lake water and tap water). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy revealed that strong ionic bonding formed during Sr(II) adsorption with the phosphate group on TiP aerogel. These results indicated that TiP aerogel is a promising high-capacity adsorbent for the effective and selective capture of Sr(II) from radioactive wastewater.
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Affiliation(s)
- Yiguo Meng
- MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, PR China
| | - Youbin Wang
- MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, PR China
| | - Zhenxiong Ye
- MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, PR China
| | - Nannan Wang
- MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, PR China
| | - Chunlin He
- MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, PR China
| | - Yanqiu Zhu
- MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, PR China
| | - Toyohisa Fujita
- MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, PR China
| | - Hanyu Wu
- Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University, Zhuhai, 519082, PR China.
| | - Xinpeng Wang
- MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, PR China.
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13
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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.
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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
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14
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Kang J, Valenzuela SA, Lin EY, Dominguez MN, Sherman ZM, Truskett TM, Anslyn EV, Milliron DJ. Colorimetric quantification of linking in thermoreversible nanocrystal gel assemblies. SCIENCE ADVANCES 2022; 8:eabm7364. [PMID: 35179967 PMCID: PMC8856611 DOI: 10.1126/sciadv.abm7364] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Nanocrystal gels can be responsive, tunable materials, but designing their structure and properties is challenging. By using reversibly bonded molecular linkers, gelation can be realized under conditions predicted by thermodynamics. However, simulations have offered the only microscopic insights, with no experimental means to monitor linking leading to gelation. We introduce a metal coordination linkage with a distinct optical signature allowing us to quantify linking in situ and establish structural and thermodynamic bases for assembly. Because of coupling between linked indium tin oxide nanocrystals, their infrared absorption shifts abruptly at a chemically tunable gelation temperature. We quantify bonding spectroscopically and use molecular simulation to understand temperature-dependent bonding motifs, revealing that gel formation is governed by reaching a critical number of effective links that extend the nanocrystal network. Microscopic insights from our colorimetric linking chemistry enable switchable gels based on thermodynamic principles, opening the door to rational design of programmable nanocrystal networks.
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Affiliation(s)
- Jiho Kang
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton St, Austin, TX 78712, USA
| | - Stephanie A. Valenzuela
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, TX 78712, USA
| | - Emily Y. Lin
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton St, Austin, TX 78712, USA
| | - Manuel N. Dominguez
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, TX 78712, USA
| | - Zachary M. Sherman
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton St, Austin, TX 78712, USA
| | - Thomas M. Truskett
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton St, Austin, TX 78712, USA
- Department of Physics, University of Texas at Austin, 2515 Speedway, Austin, TX 78712, USA
| | - Eric V. Anslyn
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, TX 78712, USA
| | - Delia J. Milliron
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton St, Austin, TX 78712, USA
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, TX 78712, USA
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15
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Hewa-Rahinduwage CC, Silva KL, Geng X, Brock SL, Luo L. Electrochemical gelation of quantum dots using non-noble metal electrodes at high oxidation potentials. NANOSCALE 2021; 13:20625-20636. [PMID: 34877956 DOI: 10.1039/d1nr06615c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Relative to conventional chemical approaches, electrochemical assembly of metal chalcogenide nanoparticles enables the use of two additional levers for tuning the assembly process: electrode material and potential. In our prior work, oxidative and metal-mediated pathways for electrochemical assembly of metal chalcogenide quantum dots (QDs) into three-dimensional gel architectures were investigated independently by employing a noble-metal (Pt) electrode at relatively high potentials and a non-noble metal electrode at relatively low potentials, respectively. In the present work, we reveal competition between the two electrogelation pathways under the condition of high oxidation potentials and non-noble metal electrodes (including Ni, Co, Zn, and Ag), where both pathways are active. We found that the electrogel structure formed under this condition is electrode material-dependent. For Ni, the major phase is oxidative electrogel, not a potential-dependent mixture of oxidative and metal-mediated electrogel that one would expect. A mechanistic study reveals that the metal-mediated electrogelation is suppressed by dithiolates, a side product from the oxidative electrogelation, which block the Ni electrode surface and terminate metal ion release. In contrast, for Co, Ag, and Zn, the electrode surface blockage by dithiolates is less effective than for Ni, such that metal-mediated electrogelation is the primary gelation pathway.
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Affiliation(s)
| | - Karunamuni L Silva
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
| | - Xin Geng
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
| | - Stephanie L Brock
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
| | - Long Luo
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
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16
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Zámbó D, Rusch P, Lübkemann F, Bigall NC. Noble-Metal Nanorod Cryoaerogels with Electrocatalytically Active Surface Sites. ACS APPLIED MATERIALS & INTERFACES 2021; 13:57774-57785. [PMID: 34813701 PMCID: PMC8662650 DOI: 10.1021/acsami.1c16424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
Noble-metal-based electrocatalysts usually contain small nanoparticle building blocks to ensure a high specific surface area as the scene for the surface processes. Here, we show that relatively large noble-metal nanorods are also promising candidates to build up functional macrostructures with prominent electrocatalytic activity. After optimizing and upscaling the syntheses of gold nanorods and gold bipyramid-templated silver nanorods, cryoaerogels are fabricated on a conductive substrate via flash freezing and subsequent freeze drying. The versatile cryoaerogelation technique allows the formation of macrostructures with dendritic, open-pore structure facilitating the increase of the accessible nanorod surfaces. It is demonstrated via electrochemical oxidation and stripping test experiments that noble-metal surface sites are electrochemically active in redox reactions. Furthermore, gold nanorod cryoaerogels offer a platform for redox sensing, ethanol oxidation reaction, as well as glucose sensing. Compared to their simply drop-cast and dried counterparts, the noble-metal nanorod cryoaerogels offer enhanced activity due to the open porosity of the fabricated nanostructure while maintaining structural stability.
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Affiliation(s)
- Dániel Zámbó
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3A, 30519 Hanover, Germany
- Centre
for Energy Research, Institute of Technical
Physics and Materials Science, Konkoly-Thege M. str. 29-33, 1121 Budapest, Hungary
| | - Pascal Rusch
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3A, 30519 Hanover, Germany
| | - Franziska Lübkemann
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3A, 30519 Hanover, Germany
| | - Nadja C. Bigall
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3A, 30519 Hanover, Germany
- Cluster
of Excellence PhoenixD (Photonics, Optics and Engineering −
Innovation Across Disciplines), Leibniz
Universität Hannover, 30167 Hanover, Germany
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17
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Schreck M, Kleger N, Matter F, Kwon J, Tervoort E, Masania K, Studart AR, Niederberger M. 3D Printed Scaffolds for Monolithic Aerogel Photocatalysts with Complex Geometries. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2104089. [PMID: 34661959 DOI: 10.1002/smll.202104089] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/30/2021] [Indexed: 06/13/2023]
Abstract
Monolithic aerogels composed of crystalline nanoparticles enable photocatalysis in three dimensions, but they suffer from low mechanical stability and it is difficult to produce them with complex geometries. Here, an approach to control the geometry of the photocatalysts to optimize their photocatalytic performance by introducing carefully designed 3D printed polymeric scaffolds into the aerogel monoliths is reported. This allows to systematically study and improve fundamental parameters in gas phase photocatalysis, such as the gas flow through and the ultraviolet light penetration into the aerogel and to customize its geometric shape to a continuous gas flow reactor. Using photocatalytic methanol reforming as a model reaction, it is shown that the optimization of these parameters leads to an increase of the hydrogen production rate by a factor of three from 400 to 1200 µmol g-1 h-1 . The rigid scaffolds also enhance the mechanical stability of the aerogels, lowering the number of rejects during synthesis and facilitating handling during operation. The combination of nanoparticle-based aerogels with 3D printed polymeric scaffolds opens up new opportunities to tailor the geometry of the photocatalysts for the photocatalytic reaction and for the reactor to maximize overall performance without necessarily changing the material composition.
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Affiliation(s)
- Murielle Schreck
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - Nicole Kleger
- Complex Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - Fabian Matter
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - Junggou Kwon
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - Elena Tervoort
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - Kunal Masania
- Complex Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - André R Studart
- Complex Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - Markus Niederberger
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
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18
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Rusch P, Pluta D, Lübkemann F, Dorfs D, Zámbó D, Bigall NC. Temperature and Composition Dependent Optical Properties of CdSe/CdS Dot/Rod-Based Aerogel Networks. Chemphyschem 2021; 23:e202100755. [PMID: 34735043 PMCID: PMC9299188 DOI: 10.1002/cphc.202100755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Indexed: 12/04/2022]
Abstract
Employing nanocrystals (NCs) as building blocks of porous aerogel network structures allows the conversion of NC materials into macroscopic solid structures while conserving their unique nanoscopic properties. Understanding the interplay of the network formation and its influence on these properties like size‐dependent emission is a key to apply techniques for the fabrication of novel nanocrystal aerogels. In this work, CdSe/CdS dot/rod NCs possessing two different CdSe core sizes were synthesized and converted into porous aerogel network structures. Temperature‐dependent steady‐state and time‐resolved photoluminescence measurements were performed to expand the understanding of the optical and electronic properties of these network structures generated from these two different building blocks and correlate their optical with the structural properties. These investigations reveal the influence of network formation and aerogel production on the network‐forming nanocrystals. Based on the two investigated NC building blocks and their aerogel networks, mixed network structures with various ratios of the two building blocks were produced and likewise optically characterized. Since the different building blocks show diverse optical response, this technique presents a straightforward way to color‐tune the resulting networks simply by choosing the building block ratio in connection with their quantum yield.
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Affiliation(s)
- Pascal Rusch
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3 A, 30167, Hannover, Germany.,Laboratory of Nano and Quantum Engineering, Leibniz Universität Hannover, Schneiderberg 39, 30167, Hannover, Germany
| | - Denis Pluta
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3 A, 30167, Hannover, Germany.,Laboratory of Nano and Quantum Engineering, Leibniz Universität Hannover, Schneiderberg 39, 30167, Hannover, Germany.,Hannover School for Nanotechnology, Leibniz Universität Hannover, Schneiderberg 39, 30167, Hannover, Germany
| | - Franziska Lübkemann
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3 A, 30167, Hannover, Germany.,Laboratory of Nano and Quantum Engineering, Leibniz Universität Hannover, Schneiderberg 39, 30167, Hannover, Germany
| | - Dirk Dorfs
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3 A, 30167, Hannover, Germany.,Laboratory of Nano and Quantum Engineering, Leibniz Universität Hannover, Schneiderberg 39, 30167, Hannover, Germany.,Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines), Leibniz Universität Hannover, 30167, Hannover, Germany
| | - Dániel Zámbó
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3 A, 30167, Hannover, Germany.,Laboratory of Nano and Quantum Engineering, Leibniz Universität Hannover, Schneiderberg 39, 30167, Hannover, Germany
| | - Nadja C Bigall
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3 A, 30167, Hannover, Germany.,Laboratory of Nano and Quantum Engineering, Leibniz Universität Hannover, Schneiderberg 39, 30167, Hannover, Germany.,Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines), Leibniz Universität Hannover, 30167, Hannover, Germany
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19
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Geng X, Li S, Mawella-Vithanage L, Ma T, Kilani M, Wang B, Ma L, Hewa-Rahinduwage CC, Shafikova A, Nikolla E, Mao G, Brock SL, Zhang L, Luo L. Atomically dispersed Pb ionic sites in PbCdSe quantum dot gels enhance room-temperature NO 2 sensing. Nat Commun 2021; 12:4895. [PMID: 34385446 PMCID: PMC8361172 DOI: 10.1038/s41467-021-25192-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/28/2021] [Indexed: 12/17/2022] Open
Abstract
Atmospheric NO2 is of great concern due to its adverse effects on human health and the environment, motivating research on NO2 detection and remediation. Existing low-cost room-temperature NO2 sensors often suffer from low sensitivity at the ppb level or long recovery times, reflecting the trade-off between sensor response and recovery time. Here, we report an atomically dispersed metal ion strategy to address it. We discover that bimetallic PbCdSe quantum dot (QD) gels containing atomically dispersed Pb ionic sites achieve the optimal combination of strong sensor response and fast recovery, leading to a high-performance room-temperature p-type semiconductor NO2 sensor as characterized by a combination of ultra-low limit of detection, high sensitivity and stability, fast response and recovery. With the help of theoretical calculations, we reveal the high performance of the PbCdSe QD gel arises from the unique tuning effects of Pb ionic sites on NO2 binding at their neighboring Cd sites.
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Affiliation(s)
- Xin Geng
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | - Shuwei Li
- Center for Combustion Energy, Tsinghua University, Beijing, China
- School of Vehicle and Mobility, Tsinghua University, Beijing, China
- State Key Laboratory of Automotive Safety and Energy, Beijing, China
| | | | - Tao Ma
- Michigan Center for Materials Characterization, University of Michigan, Ann Arbor, MI, USA
| | - Mohamed Kilani
- School of Chemical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Bingwen Wang
- Department of Chemical Engineering and Material Science, Wayne State University, Detroit, MI, USA
| | - Lu Ma
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, USA
| | | | - Alina Shafikova
- Department of Chemistry, Wayne State University, Detroit, MI, USA
| | - Eranda Nikolla
- Department of Chemical Engineering and Material Science, Wayne State University, Detroit, MI, USA
| | - Guangzhao Mao
- School of Chemical Engineering, University of New South Wales, Sydney, NSW, Australia
| | | | - Liang Zhang
- Center for Combustion Energy, Tsinghua University, Beijing, China.
- School of Vehicle and Mobility, Tsinghua University, Beijing, China.
- State Key Laboratory of Automotive Safety and Energy, Beijing, China.
| | - Long Luo
- Department of Chemistry, Wayne State University, Detroit, MI, USA.
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20
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Altenschmidt L, Sánchez-Paradinas S, Lübkemann F, Zámbó D, Abdelmonem AM, Bradtmüller H, Masood A, Morales I, de la Presa P, Knebel A, García-Tuñón MAG, Pelaz B, Hindricks KDJ, Behrens P, Parak WJ, Bigall NC. Aerogelation of Polymer-Coated Photoluminescent, Plasmonic, and Magnetic Nanoparticles for Biosensing Applications. ACS APPLIED NANO MATERIALS 2021; 4:6678-6688. [PMID: 34327308 PMCID: PMC8314273 DOI: 10.1021/acsanm.1c00636] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/26/2021] [Indexed: 06/13/2023]
Abstract
Macroscopic materials with nanoscopic properties have recently been synthesized by self-assembling defined nanoparticles to form self-supported networks, so-called aerogels. Motivated by the promising properties of this class of materials, the search for versatile routes toward the controlled assembly of presynthesized nanoparticles into such ultralight macroscopic materials has become a great interest. Overcoating procedures of colloidal nanoparticles with polymers offer versatile means to produce aerogels from nanoparticles, regardless of their size, shape, or properties while retaining their original characteristics. Herein, we report on the surface modification and assembly of various building blocks: photoluminescent nanorods, magnetic nanospheres, and plasmonic nanocubes with particle sizes between 5 and 40 nm. The polymer employed for the coating was poly(isobutylene-alt-maleic anhydride) modified with 1-dodecylamine side chains. The amphiphilic character of the polymer facilitates the stability of the nanocrystals in aqueous media. Hydrogels are prepared via triggering the colloidally stable solutions, with aqueous cations acting as linkers between the functional groups of the polymer shell. Upon supercritical drying, the hydrogels are successfully converted into macroscopic aerogels with highly porous, open structure. Due to the noninvasive preparation method, the nanoscopic properties of the building blocks are retained in the monolithic aerogels, leading to the powerful transfer of these properties to the macroscale. The open pore system, the universality of the polymer-coating strategy, and the large accessibility of the network make these gel structures promising biosensing platforms. Functionalizing the polymer shell with biomolecules opens up the possibility to utilize the nanoscopic properties of the building blocks in fluorescent probing, magnetoresistive sensing, and plasmonic-driven thermal sensing.
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Affiliation(s)
- Laura Altenschmidt
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3a, Hanover 30167, Germany
| | - Sara Sánchez-Paradinas
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3a, Hanover 30167, Germany
| | - Franziska Lübkemann
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3a, Hanover 30167, Germany
| | - Dániel Zámbó
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3a, Hanover 30167, Germany
| | - Abuelmagd M. Abdelmonem
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3a, Hanover 30167, Germany
- Food
Technology Research Institute, Agricultural
Research Center, 9 Cairo
University St., Giza 12619, Egypt
| | - Henrik Bradtmüller
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3a, Hanover 30167, Germany
- Institute
of Physical Chemistry, Westfälische
Wilhelms-Universität Münster, Corrensstraße 30, Münster D-48149, Germany
| | - Atif Masood
- Fachbereich
Physik and WZMW, Philipps Universität
Marburg, Marburg 35032, Germany
| | - Irene Morales
- Instituto
de Magnetismo Aplicado, UCM-ADIF-CSIC, Las Rozas 28230, Spain
| | | | - Alexander Knebel
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3a, Hanover 30167, Germany
- Institute
of Functional Interfaces (IFG), Karlsruhe
Institute of Technology, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
| | | | - Beatriz Pelaz
- Centro
Singular de Investigación en Química Biolóxica
e Materiais Moleculares (CiQUS), Departamento de Química Inorgánica, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Karen D. J. Hindricks
- Institute
of Inorganic Chemistry, Leibniz Universität
Hannover, Callinstr. 9, Hanover 30167, Germany
- Cluster of Excellence PhoenixD (Photonics,
Optics, and Engineering
− Innovation Across Disciplines), Hanover 30167, Germany
| | - Peter Behrens
- Institute
of Inorganic Chemistry, Leibniz Universität
Hannover, Callinstr. 9, Hanover 30167, Germany
- Cluster of Excellence
Hearing4all, Hanover 30167, Germany
- Cluster of Excellence PhoenixD (Photonics,
Optics, and Engineering
− Innovation Across Disciplines), Hanover 30167, Germany
| | - Wolfgang J. Parak
- Fachbereich
Physik und Chemie, CHyN, Universität
Hamburg, Luruper Chaussee
149, Hamburg 22607, Germany
| | - Nadja C. Bigall
- Institute
of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstr. 3a, Hanover 30167, Germany
- Cluster of Excellence PhoenixD (Photonics,
Optics, and Engineering
− Innovation Across Disciplines), Hanover 30167, Germany
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21
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Niu Y, Li F, Zhao W, Cheng W. Fabrication and application of macroscopic nanowire aerogels. NANOSCALE 2021; 13:7430-7446. [PMID: 33928971 DOI: 10.1039/d0nr09236c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Assembly of nanowires into three-dimensional macroscopic aerogels not only bridges a gap between nanowires and macroscopic bulk materials but also combines the benefits of two worlds: unique structural features of aerogels and unique physical and chemical properties of nanowires, which has triggered significant progress in the design and fabrication of nanowire-based aerogels for a diverse range of practical applications. This article reviews the methods developed for processing nanowires into three-dimensional monolithic aerogels and the applications of the resultant nanowire aerogels in many emerging fields. Detailed discussions are given on gelation mechanisms involved in every preparation method and the pros and cons of the different methods. Furthermore, we systematically scrutinize the application of nanowire-based aerogels in the fields of thermal management, energy storage and conversion, catalysis, adsorbents, sensors, and solar steam generation. The unique benefits offered by nanowire-based aerogels in every application field are clarified. We also discuss how to improve the performance of nanowire-based aerogels in those fields by engineering the compositions and structures of the aerogels. Finally, we provide our perspectives on future development of nanowire-based aerogels.
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Affiliation(s)
- Yutong Niu
- College of Materials, Xiamen University, 422 Siming South Road, Xiamen, Fujian 361005, China.
| | - Fuzhong Li
- College of Materials, Xiamen University, 422 Siming South Road, Xiamen, Fujian 361005, China.
| | - Wuxi Zhao
- College of Materials, Xiamen University, 422 Siming South Road, Xiamen, Fujian 361005, China.
| | - Wei Cheng
- College of Materials, Xiamen University, 422 Siming South Road, Xiamen, Fujian 361005, China. and Fujian Key Laboratory of Materials Genome, Xiamen University, China
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22
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Sherman ZM, Green AM, Howard MP, Anslyn EV, Truskett TM, Milliron DJ. Colloidal Nanocrystal Gels from Thermodynamic Principles. Acc Chem Res 2021; 54:798-807. [PMID: 33533588 DOI: 10.1021/acs.accounts.0c00796] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Gels assembled from solvent-dispersed nanocrystals are of interest for functional materials because they promise the opportunity to retain distinctive properties of individual nanocrystals combined with tunable, structure-dependent collective behavior. By incorporating stimuli-responsive components, these materials could also be dynamically reconfigured between structurally distinct states. However, nanocrystal gels have so far been formed mostly through irreversible aggregation, which has limited the realization of these possibilities. Meanwhile, gelation strategies for larger colloidal microparticles have been developed using reversible physical or chemical interactions. These approaches have enabled the experimental navigation of theoretically predicted phase diagrams, helping to establish an understanding of how thermodynamic behavior can guide gel formation in these materials. However, the translation of these principles to the nanoscale poses both practical and fundamental challenges. The molecules guiding assembly can no longer be safely assumed to be vanishingly small compared to the particles nor large compared to the solvent.In this Account, we discuss recent progress toward the assembly of tunable nanocrystal gels using two strategies guided by equilibrium considerations: (1) reversible chemical bonding between functionalized nanocrystals and difunctional linker molecules and (2) nonspecific, polymer-induced depletion attractions. The effective nanocrystal attractions, mediated in both approaches by a secondary molecule, compete against stabilizing repulsions to promote reversible assembly. The structure and properties of the nanocrystal gels are controlled microscopically by the design of the secondary molecule and macroscopically by its concentration. This mode of control is compelling because it largely decouples nanocrystal synthesis and functionalization from the design of interactions that drive assembly. Statistical thermodynamic theory and computer simulation have been applied to simple models that describe the bonding motifs in these assembling systems, furnish predictions for conditions under which gelation is likely to occur, and suggest strategies for tuning and disassembling the gel networks. Insights from these models have guided experimental realizations of reversible gels with optical properties in the infrared range that are sensitive to the gel structure. This process avoids time-consuming and costly trial-and-error experimental investigations to accelerate the development of nanocrystal gel assemblies.These advances highlight the need to better understand interactions between nanocrystals, how interactions give rise to gel structure, and properties that emerge. Such an understanding could suggest new approaches for creating stimuli-responsive and dissipative assembled materials whose properties are tunable on demand through directed reconfiguration of the underlying gel microstructure. It may also make nanocrystal gels amenable to computationally guided design using inverse methods to rapidly optimize experimental parameters for targeted functionalities.
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Affiliation(s)
- Zachary M. Sherman
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton Street, Austin, Texas 78712, United States
| | - Allison M. Green
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton Street, Austin, Texas 78712, United States
| | - Michael P. Howard
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton Street, Austin, Texas 78712, United States
| | - Eric V. Anslyn
- Department of Chemistry, University of Texas at Austin, 2506 Speedway, Austin, Texas 78712, United States
| | - Thomas M. Truskett
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton Street, Austin, Texas 78712, United States
- Department of Physics, University of Texas at Austin, 2515 Speedway, Austin, Texas 78712, United States
| | - Delia J. Milliron
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E Dean Keeton Street, Austin, Texas 78712, United States
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