title: Surface Defects Enhanced Visible Light Photocatalytic H2 Production for Zn-Cd-S Solid Solution.
abstract: In order to investigate the defect effect on photocatalytic performance of the visible light photocatalyst, Zn-Cd-S solid solution with surface defects is prepared in the hydrazine hydrate. X-ray photoelectron spectra and photoluminescence results confirm the existence of defects, such as sulfur vacancies, interstitial metal, and Zn and Cd in the low valence state on the top surface of solid solutions. The surface defects can be effectively removed by treating with sulfur vapor. The solid solution with surface defect exhibits a narrower band gap, wider light absorption range, and better photocatalytic perfomance. The optimized solid solution with defects exhibits 571 μmol h(-1) for 50 mg photocatalyst without loading Pt as cocatalyst under visible light irradiation, which is fourfold better than that of sulfur vapor treated samples. The wavelength dependence of photocatalytic activity discloses that the enhancement happens at each wavelength within the whole absorption range. The theoretical calculation shows that the surface defects induce the conduction band minimum and valence band maximum shift downward and upward, respectively. This constructs a type I junction between bulk and surface of solid solution, which promotes the migration of photogenerated charges toward the surface of nanostructure and leads to enhanced photocatalytic activity. Thus a new method to construct highly efficient visible light photocatalysts is opened.
authors.affiliation: State key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, CAS, 3888 East Nanhu Road, Changchun, Jilin, 130033, P. R. China.|University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, CAS, 3888 East Nanhu Road, Changchun, Jilin, 130033, P. R. China.|University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Beijing Key Laboratory of Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, 100 Pingleyuan, Beijing, 100124, P. R. China.
authors.forename: Wanwan
authors.initials: W
authors.lastname: Zhang
authors.affiliation: State key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, CAS, 3888 East Nanhu Road, Changchun, Jilin, 130033, P. R. China.|University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Zhang
authors.affiliation: State key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, CAS, 3888 East Nanhu Road, Changchun, Jilin, 130033, P. R. China.|University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
authors.forename: Dan
authors.initials: D
authors.lastname: Qu
authors.affiliation: State key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, CAS, 3888 East Nanhu Road, Changchun, Jilin, 130033, P. R. China.|University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Miao
authors.affiliation: Beijing Key Laboratory of Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, 100 Pingleyuan, Beijing, 100124, P. R. China.
authors.forename: Shaorui
authors.initials: S
authors.lastname: Sun
authors.affiliation: State key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, CAS, 3888 East Nanhu Road, Changchun, Jilin, 130033, P. R. China.|Beijing Key Laboratory of Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, 100 Pingleyuan, Beijing, 100124, P. R. China.
authors.forename: Zaicheng
authors.initials: Z
authors.lastname: Sun
keywords: H2 production; Zn-Cd-S solid solutions; enhanced photocatlytic performance; sulfur vacancies; surface defects