Novel Z-scheme W₁₈O₄₉/CeO₂ heterojunction for improved photocatalytic hydrogen evolution

The novel Z-scheme heterojunction photocatalyst W₁₈O₄₉/CeO₂ was prepared by hydrothermal synthesis. The photocatalytic properties of W₁₈O₄₉/CeO₂ were evaluated by photocatalytic hydrogen evolution under visible light. The result shows that the 15 wt% W₁₈O₄₉/CeO₂ composite has the best hydrogen production efficiency of about 0.2061 mmol g^-1h^-1, which was 1.93 times higher than that the obtained pure CeO₂. The characterization results demonstrated that the existence of Z-scheme heterojunction structure at the contact interface of W₁₈O₄₉ and CeO₂ was the origin of the enhanced photocatalytic performance for hydrogen evolution, which could greatly increase the accumulation of photo-generated electrons and the separation efficiency of charge carrier. In accordance with density functional theory (DFT) calculation, we further confirmed the formation of Z-scheme heterojunction structures. This work is anticipated to expand the ideas for modifying CeO₂ semiconductor materials to improve the rate of photocatalytic hydrogen production.