Chalcogenide cocatalysts in photocatalytic H2 production

Hydrogen is a crucial energy carrier with the potential to reduce carbon emissions and accelerate the transition to an eco-friendly future. Photocatalytic overall-water splitting (OWS) delivers a hopeful, green, and clean method for hydrogen production, but its efficiency remains unsatisfactory. This review contends that achieving high-efficiency photocatalytic OWS remains a significant challenge both theoretically and practically due to key obstacles such as asynchronized emission of O 2 and H 2 , backward/side reaction, and slow O 2 -evolution kinetics. We highlight that the sustainable trend of coupling H 2 evolution with selective organic synthesis represents a more valuable and appealing alternative. This process can be significantly promoted by the incorporation of cocatalysts. Following this demand, the function and mechanism of cocatalysts are comprehensively summarized. Then, we put a special focus on recent achievements and progress in microstructure regulation of chalcogenide cocatalysts for photocatalytic hydrogen generation, including the increase of active site numbers, improvement of active site efficiency, and acceleration of interfacial electron transfer by different strategies. Finally, we provide a forward-looking outlook on the emerging opportunities and development directions for chalcogenide cocatalysts in the materials science and catalysis fields. It is expected that this review will offer fresh insights and inspire further innovative research towards the development and optimization of highly efficient photocatalytic materials.