Anchoring Co3O4 on CdZnS to accelerate hole migration for highly stable photocatalytic overall water splitting

Photocatalytic overall water splitting represents a promising strategy to achieve the renewable hydrogen energy. Although Cd1−xZnxS catalysts show high photocatalytic hydrogen evolution efficiency in pure water, severe photocorrosion problems limit their applications. Herein, photocatalytic system composed of Co3O4 nanoparticles anchored one-dimensional Cd0.6Zn0.4S nanorods (CZS/Co3O4) is designed and prepared by a simple hydrothermal method. Transient photovoltage tests and continuous wavelet transform analyses demonstrate that Co3O4 nanoparticles efficiently capture the photogenerated holes to inhibit photocorrosion of CZS nanorods, accelerate surface charge transfer and prolong the lifetime of photogenerated carriers. The CZS/Co3O4 photocatalyst exhibits high H2 and O2 evolution rates of 83.48 and 40.48 μmol h−1 g−1, respectively. The stability is maintained over four reaction cycles without significant decrease in the absence of sacrificial agents. This work provides insight into metal sulfides against photocorrosion and extends the range of metal sulfides in solar water splitting.