In situ optical spectroscopic understanding of electrochemical passivation mechanism on sol–gel processed WO_(3) photoanodes

作     者：Jianyong Feng Xin Zhao Bowei Zhang Zhong Chen Zhaosheng Li Yizhong Huang Jianyong Feng;Xin Zhao;Bowei Zhang;Zhong Chen;Zhaosheng Li;Yizhong Huang

作者机构：Collaborative Innovation Center of Advanced MicrostructuresNational Laboratory of Solid State MicrostructuresCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210093JiangsuChina School of Materials Science and EngineeringNanyang Technological UniversitySingapore 639798Singapore 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2022年第31卷第8期

页      面：20-28,I0002页

核心收录：

学科分类：0820[工学-石油与天然气工程] 081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 

基　　金：supported by the National Natural Science Foundation of China(51902153,51972165) the Ministry of Education of Singapore Tier 1(RG193/17,RG79/20(2020-T1-001-045))。 

主　　题：In situ optical spectroscopy Electrochromism Surface trap Solar water splitting Tungsten oxide Hydrogen 

摘      要：A prevailing understanding on electrochemical activation of photoelectrodes is that electrochemical treatment leads to increased charge carrier densities thereby improved photoelectrode performances.Contrary to this understanding,in this study enhanced photoactivity of WO_(3) photoanode upon electrochemical treatment is ascribed to an extraordinary mechanism of surface trap passivation.The associated mechanism is analyzed by in situ optical spectroscopy,using which the optical property changes of WO_(3) electrode during electrochemical treatment are monitored.The results suggest surface W^(5+)species,the origin of surface traps on WO_(3) photoanodes,are converted to W^(6+) ions by electrochemical treatment.This study demonstrates the particular ability of the electrochemical strategy to passivate surface traps of photoanodes,and also shows the advantages of in situ optical spectroscopy to investigate the real-time electronic structure variations of electrodes during electrochemical treatment.