Visible light β-Bi2O3/BiOCl heterojunction photocatalyst with highly enhanced photocatalytic activity

•This is a systematic study on photocatalytic property of β-Bi2O3/BiOCl composites.•The composites exhibited highly enhanced activity for RhB degradation.•The BBC-1.5 heterojunction exhibits the best visible-light photocatalytic activity.•The heterojunctions lead to the efficient separation of electron-hole pairs.•h+ and O2− were chiefly responsible for the process of RhB degradation.