Recent Progress, Challenges, and Future Prospects in Solar H 2 Evolution via Pure/Sea Water Splitting Using Nanocomposites as Photocatalysts under Solar Light

Abstract Photocatalytic pure/sea water splitting driven by solar light, emerges as the most promising strategy to address both the global energy crisis and environmental degradation. Research efforts have mainly resulted in the development of artificial photocatalytic solar hydrogen generation systems applicable to both freshwater and sea water. During long‐term testing, sea water demonstrated enhanced stability compared to pure water, offering experimental advantages in designing novel techniques aimed at reducing hydrogen generation costs, alleviating freshwater scarcity, and optimizing the utilization of natural water resources. Moreover, sea water splitting proves to be more effective in producing solar hydrogen due to the potential sacrificial action of salt ions, which promote hydrogen evolution within the photocatalytic system. This review comprehensively outlines the fundamental principles of photocatalytic H 2 production, examines the efficiencies and recent progress in hydrogen generation, explores the challenges faced, and envisions the future prospects of enhancing hydrogen production efficiency and reactivity through photocatalytic pure/sea water splitting.