In the controlled synthesis of noble metal nanostructures using wet-chemical methods, normally, metal salts/complexes are used as precursors, and surfactants/ligands are used to tune/stabilize the morphology of nanost...In the controlled synthesis of noble metal nanostructures using wet-chemical methods, normally, metal salts/complexes are used as precursors, and surfactants/ligands are used to tune/stabilize the morphology of nanostructures. Here, we develop a facile electrochemical method to directly convert Pt wires to Pt concave icosahedra and nanocubes on carbon paper through the linear sweep voltammetry in a classic three-electrode electrochemical cell. The Pt wire, carbon paper and Ag/AgCl(3 mol L-1 KCl) are used as the counter, working and reference electrodes, respectively.Impressively, the formed Pt nanostructures exhibit better electrocatalytic activity towards the hydrogen evolution compared to the commercial Pt/C catalyst. This work provides a simple and effective way for direct conversion of Pt wires into well-defined Pt nanocrystals with clean surface. We believe it can also be used for preparation of other metal nanocrystals,such as Au and Pd, from their bulk materials, which could exhibit various promising applications.展开更多
Controllable self-assembly of noble metal nanocrystals is of broad interest for the development of highly active electrocatalysts. Here we report an efficient arginine-mediated hydrothermal approach for the high-yield...Controllable self-assembly of noble metal nanocrystals is of broad interest for the development of highly active electrocatalysts. Here we report an efficient arginine-mediated hydrothermal approach for the high-yield synthesis of cube-like Pt nanoassemblies （Pt-CNAs） with porous cavities and rough surfaces based on the self-assembly of zero dimensional Pt nanocrystals. In this process, arginine acts as the reductant, structure directing agent, and linker between adjacent nanocrystals. Interestingly, the Pt-CNAs exhibit single-crystal structures with dominant {100} facets, as evidenced by X-ray diffraction. Based on electrocatalytic studies, the as-synthesized Pt-CNAs exhibit improved electrocatalytic activity as well as good stability and CO tolerance in the methanol oxidation reaction. The Pt-CNA＇s good performance is attributed to their unique morphology and surface structure. We believe that the synthetic strategy outlined here could be extended to other rationally designed monometallic or bimetallic nanoassemblies for use in high performance fuel cells.展开更多
基金supported by the Ministry of Education under AcRF Tier 2 (ARC 19/15, No. MOE2014-T2-2-093 MOE2015-T2-2-057+6 种基金 MOE2016-T2-2-103 MOE2017-T2-1-162)AcRF Tier 1 (2016-T1-001-147 2016-T1-002-051 2017-T1-001-150 2017-T1-002-119)Nanyang Technological University under StartUp Grant (M4081296.070.500000) in Singapore
文摘In the controlled synthesis of noble metal nanostructures using wet-chemical methods, normally, metal salts/complexes are used as precursors, and surfactants/ligands are used to tune/stabilize the morphology of nanostructures. Here, we develop a facile electrochemical method to directly convert Pt wires to Pt concave icosahedra and nanocubes on carbon paper through the linear sweep voltammetry in a classic three-electrode electrochemical cell. The Pt wire, carbon paper and Ag/AgCl(3 mol L-1 KCl) are used as the counter, working and reference electrodes, respectively.Impressively, the formed Pt nanostructures exhibit better electrocatalytic activity towards the hydrogen evolution compared to the commercial Pt/C catalyst. This work provides a simple and effective way for direct conversion of Pt wires into well-defined Pt nanocrystals with clean surface. We believe it can also be used for preparation of other metal nanocrystals,such as Au and Pd, from their bulk materials, which could exhibit various promising applications.
文摘Controllable self-assembly of noble metal nanocrystals is of broad interest for the development of highly active electrocatalysts. Here we report an efficient arginine-mediated hydrothermal approach for the high-yield synthesis of cube-like Pt nanoassemblies （Pt-CNAs） with porous cavities and rough surfaces based on the self-assembly of zero dimensional Pt nanocrystals. In this process, arginine acts as the reductant, structure directing agent, and linker between adjacent nanocrystals. Interestingly, the Pt-CNAs exhibit single-crystal structures with dominant {100} facets, as evidenced by X-ray diffraction. Based on electrocatalytic studies, the as-synthesized Pt-CNAs exhibit improved electrocatalytic activity as well as good stability and CO tolerance in the methanol oxidation reaction. The Pt-CNA＇s good performance is attributed to their unique morphology and surface structure. We believe that the synthetic strategy outlined here could be extended to other rationally designed monometallic or bimetallic nanoassemblies for use in high performance fuel cells.
