In Situ Engineered G-C3n4/Zn-Mof Heterojunction for Promoting H2o2 Photogeneration: Mechanism Insights and Environmental Applications

Abstract

An efficacious photocatalyst for the sustainability of the solar-powered application is highly desirable for environmental remediation and energy conversion. In this work, in-situ coupling g-C3N4 with Zn-MOF (CN/Zn-MOF) nanosheet photocatalyst was achieved via a rapid microwave hydrothermal route. The optimized CN/Zn-MOF heterostructure demonstrated excellent photocatalytic performance. Especially, its removal efficiency of tetracycline (TC) removal efficiency was approximately twice that of the pristine g-C3N4 (p-CN), and its hydrogen production was ca. 8 times that of p-CN. The integration of g-C3N4 and Zn-MOF led to a shift of the conduction band to a negative potential value, and enhancement of the separation rate of the photogenerated electron/hole pairs and charge transfer. Moreover, the CN/Zn-MOF heterostructure facilitated the generation of H2O2, which exhibited an extended lifetime, allowing it to diffuse and interact with pollutants more effectively. This process promoted the photocatalytic degradation of TC by mediating the generation of reactive oxygen species such as single oxygen (1O2) and hydroxyl radical (‧OH). The treatment of local printing and dyeing wastewater and toxicity assessment indicated that the CN/Zn-MOF photocatalyst was capable of efficiently degrading organic pollutants and mitigating their toxicity within the aquatic ecosystem. This work shows the potential of inter-doping g-C3N4 and Zn-MOF in achieving high-performance photocatalysts by promoting H2O2 generation, and offers insights into developing advanced photocatalysts for environmental purification and energy conversion.

Keywords: Photocatalytic degradation, Microwave hydrothermal synthesis, Multifunctional photocatalyst, g-C3N4/Zn-MOF composite, Heterostructure