Construction of organic–inorganic hybrid composites derived from C3N5 incorporated with CeO2 for enhanced photocatalytic hydrogen evolution†

Energy scarcity and environmental issues can be effectively addressed via photocatalytic hydrogen production. The effective combination of semiconductor materials can prevent exciton recombination, making it a highly effective method for enhancing photocatalytic activity. This study details the synthesis of a conjugated polymer encapsulated with a metal oxide photocatalyst using a simple ex situ method. The encapsulation of the polymer with CeO₂ nanoparticles resulted in exceptional performance in H₂ production, exhibiting improved visible light absorption and a significant increase in charge transfer efficiency. This is attributed to the high charge transfer and reduced recombination in the composite. Moreover, photogenerated holes led to a substantial decline in the recombination rate of excitons and concomitant enhancement in the rate of photocatalytic H₂ production. Markedly, the observed hydrogen evolution for 10 wt% of CeO₂ doped C₃N₅ composites is 1256 μmol g⁻¹ h⁻¹, whereas for C₃N₅, it is 125 μmol g⁻¹ h⁻¹. Electrochemical analysis showed that the optimized composites exhibit a low electron–hole recombination rate, and UV-vis spectroscopic analysis showed improved visible light absorption resulting in excellent photocatalytic activity. Notably, the proposed system offers a novel strategy for hydrogen evolution via photocatalysis using CeO₂/C₃N₅ composites. Consequently, this research offers a new perspective on the design of organo–inorganic heterostructures and introduces a novel pathway to explore their catalytic capabilities.