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Qiao Y, Chen C, Liu Y, Liu Y, Dong Q, Yao Y, Wang X, Shao Y, Wang C, Hu L. Continuous Fly-Through High-Temperature Synthesis of Nanocatalysts. NANO LETTERS 2021; 21:4517-4523. [PMID: 34018760 DOI: 10.1021/acs.nanolett.0c03620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The conventional thermal treatment systems typically feature low ramping/cooling rates, which lead to steep thermal gradients that generate inefficient, nonuniform reaction conditions and result in nanoparticle aggregation. Herein, we demonstrate a continuous fly-through material synthesis approach using a novel high-temperature reactor design based on the emerging thermal-shock technology. By facing two sheets of carbon paper with a small distance apart (1-3 mm), uniform and ultrahigh temperatures can be reached up to 3200 K within 50 ms by simply applying a voltage of 15 V. The raw materials can be continuously fed through the device, allowing the final products to be rapidly collected. As a proof-of-concept demonstration, we synthesized Pt nanocatalysts (∼4 nm) anchored on carbon black via this reactor at ∼1400 K. Furthermore, we find it features excellent electrocatalytic activities toward methanol oxidation reaction. This work offers a highly efficient platform for nanomaterials synthesis at high temperatures.
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Affiliation(s)
- Yun Qiao
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Chaoji Chen
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Yang Liu
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Yifan Liu
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Qi Dong
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Yonggang Yao
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Xizheng Wang
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Yuyan Shao
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Chao Wang
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Liangbing Hu
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
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Chen C, Song J, Cheng J, Pang Z, Gan W, Chen G, Kuang Y, Huang H, Ray U, Li T, Hu L. Highly Elastic Hydrated Cellulosic Materials with Durable Compressibility and Tunable Conductivity. ACS NANO 2020; 14:16723-16734. [PMID: 32806053 DOI: 10.1021/acsnano.0c04298] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Anisotropic cellular materials with direction-dependent structure and durable mechanical properties enable various applications (e.g., nanofluidics, biomedical devices, tissue engineering, and water purification), but their widespread use is often hindered by complex and scale-limited fabrication and unsatisfactory mechanical performance. Here, inspired by the anisotropic and hierarchical material structure of tendons, we demonstrate a facile, scalable top-down approach for fabricating a highly elastic, ionically conductive, anisotropic cellulosic material (named elastic wood) directly from natural wood via chemical treatment. The resulting elastic wood demonstrates good elasticity and durable compressibility, showing no sign of fatigue after 10 000 compression cycles. The chemical treatment not only softens the wood cell walls by partially removing lignin and hemicellulose but introduces an interconnected cellulose fibril network into the wood channels. Atomistic and continuum modeling further reveals that the absorbed water can freely and reversibly move inside the elastic wood and therefore helps the elastic wood accommodate large compressive deformation and recover to its original shape upon compression release. In addition, the elastic wood showed a high ionic conductivity of up to 0.5 mS cm-1 at a low KCl concentration of 10-4 M, which can be tuned by changing the compression ratio of the material. The demonstrated elastic, mechanically robust, and ionically conductive cellulosic material combining inherited anisotropic cellular structure from natural wood and a self-formed internal gel may find a variety of potential applications in ionic nanofluidics, sensors, soft robots, artificial muscle, environmental remediation, and energy storage.
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Affiliation(s)
- Chaoji Chen
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Jianwei Song
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Jian Cheng
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Zhenqian Pang
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Wentao Gan
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Gegu Chen
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Yudi Kuang
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Hao Huang
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Upamanyu Ray
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Teng Li
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Liangbing Hu
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
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Dang T, Wei D, Zhang G, Wang L, Li Q, Liu H, Cao Z, Zhang G, Duan H. Homologous NiCoP/CoP hetero-nanosheets supported on N-doped carbon nanotubes for high-rate hybrid supercapacitors. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.135988] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Liu T, Dou X, Xu Y, Chen Y, Han Y. In Situ Investigation of Dynamic Silver Crystallization Driven by Chemical Reaction and Diffusion. RESEARCH 2020; 2020:4370817. [PMID: 32118207 PMCID: PMC7035454 DOI: 10.34133/2020/4370817] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 01/09/2020] [Indexed: 11/06/2022]
Abstract
Rational synthesis of materials is a long-term challenging issue due to the poor understanding on the formation mechanism of material structure and the limited capability in controlling nanoscale crystallization. The emergent in situ electron microscope provides an insight to this issue. By employing an in situ scanning electron microscope, silver crystallization is investigated in real time, in which a reversible crystallization is observed. To disclose this reversible crystallization, the radicals generated by the irradiation of electron beam are calculated. It is found that the concentrations of radicals are spatiotemporally variable in the liquid cell due to the diffusion and reaction of radicals. The fluctuation of the reductive hydrated electrons and the oxidative hydroxyl radicals in the cell leads to the alternative dominance of the reduction and oxidation reactions. The reduction leads to the growth of silver crystals while the oxidation leads to their dissolution, which results in the reversible silver crystallization. A regulation of radical distribution by electron dose rates leads to the formation of diverse silver structures, confirming the dominant role of local chemical concentration in the structure evolution of materials.
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Affiliation(s)
- Ting Liu
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 100190 Beijing, China.,State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, 570228 Haikou, China
| | - Xiangyu Dou
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 100190 Beijing, China.,School of Chemical Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Yonghui Xu
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 100190 Beijing, China.,School of Chemical Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Yongjun Chen
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, 570228 Haikou, China
| | - Yongsheng Han
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 100190 Beijing, China.,School of Chemical Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
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