Advanced modification strategies of CdS-based photocatalysts for enhanced green hydrogen production

Abstract

Solar-driven photocatalytic water-splitting offers a promising route toward sustainable hydrogen (H₂) production and decarbonization. The search for cost-effective and highly active photocatalysts has directed considerable attention toward semiconductor materials, among which cadmium sulfide (CdS) has garnered significant interest due to its inherent physicochemical properties and strong visible-light absorption resulting from its suitable bandgap (∼2.4 eV). Nevertheless, poor quantum efficiency, photocorrosion, and fast charge carrier recombination restrict its practical application. In this context, significant research efforts have been devoted to improving the photocatalytic performance of CdS through various material engineering strategies. This review provides a comprehensive and critical evaluation of recent advances in CdS-based photocatalysts, with a particular emphasis on identifying the origin of performance limitations and correlating structural and electronic modulation with photocatalytic activity. The key novelty of this work lies in the integrated discussion of advanced engineering approaches, including defect engineering, heterojunction and core–shell architecture design, cocatalyst loading, and elemental doping strategies, and their collective influence on charge separation dynamics, photostability, and H₂ evolution efficiency. Furthermore, the emerging mechanistic insights and structure–property relationships are analyzed to bridge experimental progress with theoretical understanding using density functional theory. This review also emphasizes scale-up strategies for practical H₂ production, discussing the challenges and prospects of translating laboratory-scale photocatalysis into large-scale solar H₂ generation systems. Finally, future research directions and design principles are proposed to facilitate the development of highly efficient and scalable CdS-based photocatalytic systems for sustainable H₂ production.