Open AccessRational construction of Au–Ag bimetallic island-shaped nanoplates for electrocatalysis
Author(s) -
Hong Zhao,
Diandian Liu,
Shujuan Xu,
Yao Chen,
Fan Yin,
Tao Yang,
Mingyan Wang,
Hua Deng,
Wei Zhang,
Weiwei Liu,
Xiaohong Liu
Publication year - 2020
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ab726e
Subject(s) - electrocatalyst , bimetallic strip , catalysis , nanostructure , materials science , nanotechnology , galvanic cell , polyvinylpyrrolidone , chemical engineering , water splitting , single displacement reaction , electrolysis , crystal (programming language) , electrolyte , chemistry , electrode , metallurgy , electrochemistry , photocatalysis , computer science , polymer chemistry , engineering , programming language , biochemistry
Active electrocatalysts are the key to water splitting for hydrogen production through the electrolysis. In this paper, 50 nm silver nanoplates were used as templates for synthesis of Au–Ag island-shaped nanoplates by controlling the surface chemistry. The guiding mechanism of polyvinylpyrrolidone (PVP, Mw = 40 000) to Au–Ag island-shaped nanoplates crystal was also further investigated. It is found that the surface energy of Ag nanoplates between (100) and (111) crystal planes can be regulated by varying the amount of PVP in the system. Then a uniform Au-Ag triangular island nanostructure was obtained. Compared with the Ag nanoplates catalysts, the Au–Ag island nanoplates catalysts show the superior catalytic performances in hydrogen evolution electrocatalysis (HER). These results demonstrate a new surface chemistry modification by PVP and a galvanic displacement reaction for designing the active electrocatalysts. More importantly, the Au–Ag island-shaped nanoplates show an unconventional growth mode of preserving the original Ag nano-triangular crystal structure. The enhanced performance in electrocatalysis can be mainly attributed to Au–Ag alloy structure, which allows the appearance of synergistic effects. The present work demonstrates the crucial roles of surface chemistry in catalysts synthesis, which may guide the design of active bimetallic catalysts.