Defect-induced atomic-level intimate interface of a hollow Ov-CeO2/CdS photocatalyst with a Z-scheme to boost hydrogen evolution

Abstract

Construction of Z-scheme heterojunction catalysts with high-speed charge transfer channels for efficient photocatalytic hydrogen production from water splitting is still a challenge. In this work, a lattice-defect-induced atom migration strategy is proposed to construct an intimate interface. The oxygen vacancies of cubic CeO2 obtained from a Cu2O template are used to induce lattice oxygen migration and form SO bonds with CdS to form a close contact heterojunction with a hollow cube. The hydrogen production efficiency reaches ∼12.6 mmol·g−1·h−1 and maintains a high value over 25 h. A series of photocatalytic tests combined with density functional theory (DFT) calculations show that the close contact heterostructure not only promotes the separation/transfer of photogenerated electron-hole pairs but also regulates the intrinsic catalytic activity of the surface. A large number of oxygen vacancies and SO bonds at the interface participate in charge transfer, which accelerates the migration of photogenerated carriers. The hollow structure improves the ability to capture visible light. Therefore, the synthesis strategy proposed in this work, as well as the in-depth discussion of the interface chemical structure and charge transfer mechanism, provides new theoretical support for the further development of photolytic hydrogen evolution catalysts.