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High‐Performance and Stable Silicon Photoanode Modified by Crystalline Ni@ Amorphous Co Core‐Shell Nanoparticles
Author(s) -
Chen Jie,
Xu Guangzhou,
Wang Chao,
Zhu Kai,
Wang Hongxu,
Yan Shicheng,
Yu Zhentao,
Zou Zhigang
Publication year - 2018
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201801417
Subject(s) - materials science , nanoparticle , water splitting , semiconductor , amorphous solid , reversible hydrogen electrode , electrolyte , chemical engineering , band bending , work function , nanotechnology , electrode , optoelectronics , layer (electronics) , crystallography , chemistry , working electrode , catalysis , biochemistry , photocatalysis , engineering
Abstract Improving the charge separation and transport efficiency at semiconductor‐electrolyte interface is critical for high‐performance photoelectrochemical (PEC) water‐splitting devices. Here, the core‐shell‐structured Ni@Co nanoislands were electrodeposited onto the surface of n‐type Si photoanode to construct a metal‐insulator‐semiconductor (MIS) structure. We discover that the high‐quality interface in Si/SiO x /Ni MIS structure is more efficient for charge extraction and transfer than Si/SiO x /Co. Owing to a slightly higher work function for Co (5.0 eV) than Ni (4.6 eV), the Si/SiO x /Ni@Co exhibits the larger band bending to enhance the charge separation efficiency, while the in‐situ formed CoOOH significantly increases the charge injection efficiency due to the decreased oxygen‐evolution overpotentials. As a result, the Ni@Co core‐shell nanoparticles coupling with n‐Si photoanode can afford the PEC performance with an onset potential of 1.02 V versus reversible hydrogen electrode (RHE), saturated current density of 36.7 mA cm −2 , and retain good stability in K‐borate buffer solution. This core‐shell structure strategy is efficient and easy to achieve the separation of photogenerated carriers and improve the charge injection efficiency to nearly 100 %