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

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 + /H 2 and O 2 /H 2 O. In this paper, Sillen-Aurivillius compounds with layered structure Bi 3 O 4 Cl and Y 3 O 4 Cl solid solution (Bi 3−x Y x O 4 Cl) were successfully synthesized by the solid-phase method. The absorption edge of Bi 3−x Y x O 4 Cl 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 Bi 3−x Y x O 4 Cl 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 Bi 3−x Y x O 4 Cl all satisfied the redox potential for H + /H 2 , which showed excellent visible-light photocatalytic water splitting.