期刊
ACS CATALYSIS
卷 8, 期 4, 页码 3331-3342出版社
AMER CHEMICAL SOC
DOI: 10.1021/acscatal.7b04277
关键词
bismuth vanadate; water splitting photoanode; tungsten doping; surface states
资金
- Generalitat de Catalunya [2017SGR1246]
- China Scholarship Council [201606510020]
- European Regional Development Funds (ERDF, FEDER)
- MINECO [ENE2016-80788-C5-5-R, FJCI-2014-19745]
- European Union
- Agency for Business Competitiveness of the Government of Catalonia [712939]
- Fundamental Research Funds for the Central Universities [2016ZCQ03]
- Beijing Natural Science Foundation [8172035]
The nanostructured BiVO4 photoanodes were prepared by electrospinning and were further characterized by XRD, SEM, and XPS, confirming the bulk and surface modification of the electrodes attained by W addition. The role of surface states (SS) during water oxidation for the as prepared photoanodes was investigated by using electro-chemical, photoelectrochemical, and impedance spectroscopy measurements. An optimum 2% doping is observed in voltammetric measurements with the highest photocurrent density at 1.23 V-RHE under back side illumination. It has been found that a high PEC performance requires an optimum ratio of density of surface states (N-SS) with respect to the charge donor density (N-d), to give both good conductivity and enough surface reactive sites. The optimum doping (2%) shows the highest Nd and SS concentration, which leads to the high film conductivity and reactive sites. The reason for SS acting as reaction sites (i-SS) is suggested to be the reversible redox process of V5+/V4+ in semiconductor bulk to form water oxidation intermediates through the electron trapping process. Otherwise, the irreversible surface reductive reaction of VO2+ to VO2+ though the electron trapping process raises the surface recombination. W doping does have an effect on the surface properties of the BiVO4. electrode. It can tune the electron trapping process to obtain a high concentration of i-SS and less surface recombination. This work gives a further understanding for the enhancement of PEC performance caused by W doping in the field of charge transfer at the semiconductor/electrolyte interface.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据