Recent advances in cocatalyst engineering for solar-driven overall water splitting

Solar-driven overall water splitting using particulate photocatalysts represents a viable and attractive paradigm to produce H₂. To achieve sustainable artificial photosynthesis, considerable effort has been devoted in enhancing the overall efficiency and stability of photocatalysts. More specifically, modifying the photocatalyst surface with suitable cocatalysts can significantly enhance its water-splitting performance. In this minireview, we describe recent advances with respect to the hybridization strategies in constructing high-performance cocatalyst/photocatalyst systems. We first discuss the fundamental concepts and principles governing the photocatalytic water splitting and the important role of cocatalysts. Subsequently, we examine the strengths and drawbacks of conventional and emerging cocatalyst loading strategies. Special consideration is given to the structure–activity relationship of cocatalysts to achieve efficient photocatalytic H₂ production from pure H₂O. Finally, the remaining key challenges and possible future directions in the discovery and further exploration of cocatalyst materials are also discussed. We anticipate this review will provide insights and inspire more research interest in designing high-performance cocatalysts for photocatalytic overall water splitting.