The Sn 2+ ion self-doping CdS/ZnSnO 3 hollow core−shell cubic heterojunction photocatalyst is fabricated via an approach of hybrid coprecipitation-annealing-reduction-chemical method. As reported, the as-prepared CdS/Sn 2+ −ZnSnO 3 heterojunction exhibits prominent enhanced photocatalytic hydrogen evolution reaction (HER, ∼5218.71 μmol•g −1 •h −1 , Na 2 S + Na 2 SO 3 sacrificial agent) and degradation than that of ZnSnO 3 (∼120/8.3folds) and CdS (∼50/5.2-folds). There, the CdS/Sn 2+ -ZSO with a greater potential gradient can promote the carrier separation; CdS with a higher absorption can increase the visible-light response; and the Sn 2+ /O v with a shallow donor level can regulate the potential structure, increase the intrinsic carrier injection, and promote the carrier transportation. All of these can optimize the carrier efficiency effectively, including increasing the transportation, prolonging the lifetime, and decreasing the recombination. In addition, the CdS nanoshell can provide vast active sites and the hollow cubic structure with large internal cavities can enhance the solar efficiency, while retaining good stability during photocatalysis.