Preparation of ox-GQDs/PCNO and its visible-light photocatalytic activities

• 1、School of Food Science and Technology, Jiangnan University, Wu Xi 214122

Abstract：Herein, oxidized nanoporous g-C3N4 (PCNO) decorated with co-catalyst graphene oxide quantum dots (ox-GQDs) was successfully achieved by a facile self-assembly method. The morphology and structure of the photocatalysts were characterized by TEM, XRD and XPS, etc. and their photocatalytic degradation and disinfection performance were also evaluated. In contrast with PCNO, ox-GQDs/PCNO composite photocatalysts possessed expanded light response range, accelerated charge transfer efficiency, strengthened photooxidation ability and more active species due to the up-conversion property, strong electronic capture ability,and peroxidase-like activity of ox-GQDs. Therefore, the visible-light-driven photocatalytic degradation and disinfection performance of ox-GQDs/PCNO are significantly enhanced. Remarkably, the composite with a depositing amount of 0.2 wt% (ox-GQDs-0.2%/PCNO) exhibited the optimum photodegradation activity on pigment amaranth, which was about 3.1 times faster than that of PCNO. Meanwhile, ox-GQDs-0.2%/PCNO could inactivate about 99.6% of Escherichia coli (E. coli) cells after 4 h of irradiation treatment, whereas only about 31.9% of E. coli cells were killed by PCNO. Furthermore, h+, oO2? and oOH were verified to be the reactive species generated in the photocatalytic process of ox-GQDs/PCNO system which can thoroughly mineralize azo pollutants and effectively inactivate pathogenic bacteria.

Keywords： Photocatalysis Oxidized nanoporous g-C3N4 Graphene oxide quantum dots Degradation Disinfection Visible light