Regulating the Si/Al ratio of g-C3N4/HBeta to improve adsorption and catalytic activity for enhancing photocatalytic pollutant degradation and H2 production

The rational modulation of the Si/Al ratio within molecular sieves holds utmost significance for augmenting photocatalytic activity. In this context, g-C 3 N 4 /HBeta composite photocatalysts were synthesised via a straightforward in situ thermal polymerisation procedure employing HBeta molecular sieves possessing multiple active sites and diverse Si/Al ratios. Through the variation of Si/Al ratios, the adsorption capacity, photogenerated carrier complexation efficiency, and active site characteristics could be effectively manipulated. The catalyst with the smallest Si/Al ratio (HBeta 25 ) exhibited the highest catalytic activity, with a hydrogen production efficiency of 2.346 mmol g⁻¹. This value was 4.9 times higher than that of pure g-C 3 N 4 , and the degradation efficiency of RhB was 3 times that of pure g-C 3 N 4 . The catalytic proficiency was principally validated by employing a comprehensive suite of techniques, including XPS, BET, SEM, and NH 3 -TPD. Our results demonstrate for the first time the strong potential of zeolite Si/Al ratio to modulate the catalytic activity of photocatalysts.