A Facile In₂S₃-CoS₂ Dual-Component Photocatalyst for H₂O₂ Generation

Abstract

Photocatalytic production of hydrogen peroxide (H₂O₂) remains challenged by rapid recombination of photogenerated charge carriers, limited activity of single component photocatalysts, and the need for simple, practical systems with enhanced performance. In this study, metal chalcogenide photocatalysts based on In₂S₃ and CoS₂ were developed via a straightforward physical mixing strategy to improve H₂O₂ generation. Pure In₂S₃ and CoS₂ were synthesized individually and combined in various ratios, and electrospun polyacrylonitrile (PAN) supported catalyst fibers were also fabricated to investigate immobilized photocatalytic systems. Among the prepared samples, the In₂S₃/CoS₂ (4:1) composite exhibited the highest activity, with an optimal catalyst loading of 15 mg, producing 43.0 μM H₂O₂ after 60 min of irradiation under a full-spectrum xenon lamp. The enhanced performance is attributed to strong interfacial interactions between In₂S₃ and CoS₂, which promote efficient charge separation, suppress electron–hole recombination, and facilitate oxygen reduction to H₂O₂. Although the electrospun fiber-based systems showed lower activity than the powder composites, they demonstrated measurable photocatalytic performance, indicating their potential for further optimization as recoverable catalyst systems. Overall, this work demonstrates that simple physical mixing of metal chalcogenides is a cost-effective strategy to enhance photocatalytic H₂O₂ production and provides valuable insight into the role of interfacial interactions in designing efficient catalysts for sustainable solar-driven H₂O₂ generation.