Screen superior ultra-thin g-C3N4 material for photocatalytic in-situ H2O2 production to remove tetracycline

Abstract

Photocatalytic in-situ hydrogen peroxide (H2O2) preparation for cascade reactions is a novel and promising application strategy, especially for environmental remediation. Graphitic carbon nitride (g-C3N4) has been proven to be one of the most effective catalysts. However, the H2O2 yields on g-C3N4 materials fabricated by different precursors varied greatly, so that the reasons need to be explored urgently for the later using. In this work, a series of different ultra-thin g-C3N4 nanosheets catalysts are synthesized, on which the H2O2 generation and tetracycline removal abilities are evaluated comprehensively. Among these, the g-C3N4 nanosheets prepared by dicyandiamide (DCN) is demonstrated the excellent one with the maximum H2O2 production efficiency of 665.4 μmol h−1 g−1, and its apparent quantum yield (AQY) arrives to 9.3% when illuminated at 400 nm. The superior photocatalytic performance of DCN is attributed to its nearly two-electron (2e-) oxygen reduction reaction (ORR) process, numerous unpaired electrons, suitable band structure, rapid charge separation and transfer efficiency. This work provides an effective strategy for wastewater purification without adding H2O2, which has screened an excellent ultra-thin g-C3N4 catalyst, for the further photocatalysis research.