Rational construction of p-n-p CuO/CdS/CoWO4 S-scheme heterojunction with influential separation and directional transfer of interfacial photocarriers for boosted photocatalytic H2 evolution

In order to hydrogen evolution by water splitting, with appropriate design, the effective sites of the efficient heterostructured photocatalysts are boosted, and the directional transfer of the photo carriers is ensured. In this paper, we report the p-n-p heterostructured CuO/CdS/CoWO4 nanocomposite formed with CoWO4 deposited using microwave method on CuO/CdS prepared by combining CuO and CdS synthesized by hydrothermal method and microwave method, respectively. In the asset of an electric field formed by the S-scheme heterostructure of p-n-p CuO/CdS/CoWO4, efficient directional transfer of charge carriers is achieved and recombination of beneficial charge carriers is suppressed. The rate of hydrogen evolution is 457.9 μmol g−1 h−1 in the existence of CuO/CdS/CoWO4, which is 3.14, 11.99, 40.88 and 102.9, times as that of CuO/CdS, CdS, CuO and CoWO4, respectively. This study offers new perspectives on the preparation of p-n-p type rationally designed photocatalysts with improved photocatalytic efficiency and stability for hydrogen generation applications.