Emerging Trends in CdS‐Based Nanoheterostructures: From Type‐II and Z‐Scheme toward S‐Scheme Photocatalytic H₂ Production

Abstract

Cadmium sulfide (CdS) based heterojunctions, including type‐II, Z‐scheme, and S‐scheme systems emerged as promising materials for augmenting photocatalytic hydrogen (H2) generation from water splitting. This review offers an exclusive highlight of their fundamental principles, synthesis routes, charge transfer mechanisms, and performance properties in improving H2 production. We overview the crucial roles of Type‐II heterojunctions in enhancing charge separation, Z‐scheme heterojunctions in promoting redox potentials to reduce electron‐hole (e−/h+) pairs recombination, and S‐scheme heterojunctions in combining the merits of both type‐II and Z‐scheme frameworks to obtain highly efficient H2 production. The importance of this review is demonstrated by its thorough comparison of these three configurations, presenting valuable insights into their special contributions and capability for augmenting photocatalytic H2 activity. Additionally, key challenges and prospects in the practical applications of CdS‐based heterojunctions are addressed, which provides a comprehensive route for emerging research in achieving sustainable energy goals.