A visualizable means for verifying the manner of charge transfer in WO3-based type-II heterostructuresElectronic supplementary information (ESI) available: Fig. S1 and Table S1. See DOI: 10.1039/c9nr00661c

• Main Authors: Zhang, Lulu, Yuan, Jie, Jiang, Cankun, Huang, Xueyan, Zhao, Yan, Gao, Fan, Fang, Zhibin, Liu, Ping
• Format: Journal Article
• Language: English
• Published: 23.04.2019
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c9nr00661c

Research into photocatalytic mechanisms and charge carrier transfer is of vital significance. For type-II heterostructures containing WO 3 , a visualizable means is proposed for the first time for verifying the manner of charge transfer via observing the photochromism of WO 3 . The accuracy of this visualizable means is evidenced through corresponding characterization, such as XPS and OCP. In addition, photocatalytic H 2 evolution as a supporting proof is studied to prove the manner of charge transfer owing to the inactivity of WO 3 . If the charge transfer pathway principally follows a conventional type-II manner, the heterostructure will change color from yellow to a dark color and show lower activity compared with the individuals. However, if the charge transfer primarily follows a Z-scheme mechanism, the color won't show a noticeable change but much higher activity will be exhibited than that by the individual components. CdS-WO 3 and ZnIn 2 S 4 -WO 3 (ZIS-WO 3 ) are used as examples to verify the universality of this method and exclude the impact of the crystal phase of WO 3 on photochromism. Research into photocatalytic mechanisms and charge carrier transfer is of vital significance.