ZnO/ZnS/CdS three-phase composite photocatalyst with a flower cluster structure: Research on its preparation and photocatalytic activity hydrogen production

The ZnO/ZnS/CdS three-phase composite photocatalyst with a flower cluster structure was successfully synthesized in three steps with ammonia as the hydrothermal solvent. The photocatalyst showed excellent photocatalytic activity for hydrogen production with a rate of photocatalytic hydrogen production up to 2.64 mmol h−1 g−1 and the photocatalyst also exhibited perfect stability, and the photoactivity displayed no significant degradation during continuous hydrogen production over nearly 72 h. Further detailed characterizations revealed that the CdS in the ZnO/ZnS/CdS photocatalyst uniformly wrapped on the surface of ZnS. The presence of ZnS improved the hydrogen generation overpotential of CdS in the ZnO/ZnS/CdS photocatalyst. The position of the valence band for ZnO in the ZnO/ZnS/CdS photocatalyst was more negative than that of CdS, so the photocatalytic oxidation reaction occurred in the valence band of ZnO rather than that of CdS. The above results greatly improved photocatalytic activity of hydrogen production and photocatalytic stability for the ZnO/ZnS/CdS photocatalyst.