Green and alcohol-free H₂O₂ generation paired with simultaneous contaminant treatment enabled by sulfur/cyano-modified g-C₃N₄ with efficient oxygen activation and proton adsorption

Photocatalytic H2O2 generation is compelling for sustainable solar-to-chemical conversion, but it is an emerging challenge to realize efficient conversion without the consumption of any alcohols. Also, the in-depth mechanism for the structure-induced activity enhancement is still unclear but remains pivotal for practical application. Herein, cyano groups and S atoms were collectively introduced into carbon nitride (MTCN), and the vital roles and detailed mechanism were investigated. Specifically, MTCN exhibited a laudable H2O2 generation of 68.12 mM g(cat)(-1) h(-1), together with an apparent quantum yield of 49.01% at 420 nm. Intriguingly, it was observed that the existence of some contaminants can promote H2O2 generation and, in turn, accelerate degradation. Additionally, it is revealed that the S atoms and cyano group could facilitate oxygen adsorption and H+ adsorption, respectively. This study shows a promising strategy to construct modified g-C3N4 and exhibits a clear mechanism for H2O2 generation paired with simultaneous contaminant treatment.