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

Abstract

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.