Preparation of core-shell-like Bi₂WO₆/BiOCl heterojunction with excellent visible-light photocatalytic activity

Constructing a ‘Z-scheme’ heterojunction is an effective method for improving photocatalyst activity. Core-shell-like Z-scheme bismuth tungstate (Bi₂WO₆)/bismuth oxychloride (BiOCl) heterojunction was synthesized through a two-step method. The arbutus-like bismuth oxychloride microsphere core was first gained by a solvothermal method. Then the Bi₂WO₆ nanosheet shell was in situ on the surface of the BiOCl microsphere through another solvothermal process. The bismuth tungstate/bismuth oxychloride heterojunction had a much better photocatalytic performance than that of the single bismuth tungstate, which was due to the enlarged BET surface area, enhanced light absorption, and photocarriers’ migration. The photocatalytic mechanism of the bismuth tungstate/bismuth oxychloride heterojunction was also proposed.