Solid-phase synthesis of Bi3−xYxO4Cl solid solution for visible-light photocatalytic hydrogen generation

•Bi3−xYxO4Cl solid solution were successfully synthesized by solid-phase method.•The absorption edge of Bi3−xYxO4Cl could be adjusted from about 500–740 nm.•The conduction band minimum energy satisfied the redox potential for both H+/H2.•Bi3−xYxO4Cl solid solution showed the visible light photocatalytic H2 evolution activity. [Display omitted] The solid solution constructed by two or more semiconductors with different bandgaps can effectively modulate the energy band, satisfying the redox potential for both H+/H2 and O2/H2O. In this paper, Sillen-Aurivillius compounds with layered structure Bi3O4Cl and Y3O4Cl solid solution (Bi3−xYxO4Cl) were successfully synthesized by the solid-phase method. The absorption edge of Bi3−xYxO4Cl could be dramatically changed from about 500–740 nm with the increase of Bi elements, which accounted for the entire UV-Vis region of the solar spectrum. Furthermore, the bandgaps for Bi3−xYxO4Cl could be adjusted from about 2.6–2.0 eV with the decreased Y/Bi ratio from 2 to 0.2. Significantly, the conduction band minimum energy (CBM) of Bi3−xYxO4Cl all satisfied the redox potential for H+/H2, which showed excellent visible-light photocatalytic water splitting.