Photocorrosion-Resistant ZnCo₂S₄/CdS Z-Scheme Heterojunction for Efficient Co-production of Aromatic Aldehydes and Hydrogen

Photocatalytic water splitting is one of the most promising technologies for hydrogen production in the future, which, however, may suffer from serious photocorrosion of photocatalysts in practical applications. In this study, a ZnCo₂S₄/CdS Z-scheme heterojunction has been successfully constructed, which demonstrates not only much improved cyclic stability of the catalyst but also enhanced photocatalytic activity for the co-photocatalysis of aromatic alcohols and water under visible light. The optimized 60% ZnCo₂S₄/CdS shows an especially high photocatalytic hydrogen evolution rate of 214.8 μmol/h and up to 93% selectivity for p-methyl benzaldehyde (p-CH₃BAD). More importantly, a ZnCo₂S₄-assisted CdS regeneration mechanism has been proposed for the first time, which offers new insight into solving the stability and environmental pollution concerns of CdS-based photocatalysts.