Driving tetracycline hydrochloride degradation and concomitant hydrogen peroxide photosynthesis in a neutral environment over sulphur and oxygen codoped carbon nitride

Abstract

The investigation of an artificial photosynthesis system for contaminant treatment and consecutive hydrogen peroxide formation is imperative but challenging, whereas the conversion efficiency is relatively low and far away from the demand for social development. Herein, oxygen and sulphur were collectively introduced into carbon nitride nanosheets (OSCN), together with sufficient edge and basal plane active sites. The as-synthesized sample could achieve a degradation efficiency of 84% for 100 mg/L tetracycline hydrochloride, together with simultaneous hydrogen peroxide production of 366 μmol g−1 h−1 under environmentally friendly neutral conditions. Intriguingly, the addition of tetracycline hydrochloride can accelerate hydrogen peroxide generation, which thus in turn speed up tetracycline hydrochloride degradation. It was revealed that the optimized electronic structure, promoted light-harvesting, and enhanced charge carriers separation capacity are conducive for the synchronous oxygen reduction and contaminant oxidation procedure in large measure. Furthermore, the degradation and hydrogen peroxide generation can be maintained even after 15 cycles, demonstrating the stability of OSCN and its possibility for practical applications. The degradation pathway and in-deep reaction mechanism are carried out accordingly. Additionally, such a synchronously promoted reaction can be extended to some other pollutants, like phenol and 2,4-dichlorophenol. This interesting work provides a novel strategy for pollutants removal and concurrent hydrogen peroxide generation.