Highly efficient H-2 evolution over ZnO-ZnS-CdS heterostructures from an aqueous solution containing SO32- and S2- ions

ZnO-ZnS-CdS heterostructure photocatalysts for water splitting were designed and prepared by a wet chemistry method. It was found that ZnO-ZnS-CdS heterostructures are highly active photocatalysts for H-2 evolution under simulated solar light irradiation in an aqueous solution containing SO32- and S2- ions as sacrificial reagents. H-2 evolution with (ZnO)(2)-(ZnS)(1)-(CdS)(1) heterostructure reaches up to 2790 mu mol h(-1) g(-1). The photoexcited electrons in the ZnO-ZnS-CdS heterostructures have a much longer lifetime (>225 ns) than that of the sole ZnO, ZnS, and CdS (<65 ns). The favorable interface processes of the heterostructures make a significant contribution to high photocatalytic H-2 evolution rate.