Progress of the key catalyst for solar photolysis of water to produce hydrogen and research on multi-field coupling

Solar photolysis of water to produce hydrogen can fundamentally solve the problems of energy demand and environmental pollution caused by carbon emissions, which is one of the hot topics in the world. The use of solar full-spectrum photocatalysis for hydrogen production is the main research method currently, but the catalytic efficiency is low and it is difficult to be applied in practice. The main factors leading to the low photocatalytic efficiency are small specific surface area, weak light absorption capacity, wide band gap width and weak carrier mobility. In this paper, the mechanism of photocatalysis and the optimization strategy of photocatalyst are summarized. Through the strategies such as sensitization material doping, element doping, hetero-structure construction, co-catalyst loading, high-conductivity graphene doping, etc., the visible light absorption of photocatalyst is improved effectively, the recombinations of photo-generated carriers are reduced, active sites are increased and surface reactions are accelerated. In addition, the multi-field coupling catalytic hydrogen production developed in recent years, such as photo-electric, photothermal and photothermalelectric catalysis, has been systematically introduced, and the fu-ture development of the theory and practice of solar hydrogen production catalysts have been prospected.