Pyridinic N–reduced graphene oxide and ZnO composite synergistically enhance photocatalytic performance

Abstract

This paper reports the synthesis of nitrogen-doped reduced graphene oxide (N-rGO)/zinc oxide (ZnO) composite photocatalysts by one-step hydrothermal method. Taking urea as the nitrogen source, ammonia is released at high temperature, and reduced graphene oxide (rGO) has a strong adsorption effect on ammonia, which is more conducive to improving the nitrogen doping efficiency in the nitrogen doping process. The results of the dye degradation test showed that when the nitrogen content was 4 wt%, the photocatalytic degradation ability of the catalyst was the best, which was 88% higher than that of pure zinc oxide. The X-ray photoelectron spectroscopy (XPS) test showed that the catalytic effect of the sample dominated by pyridinic nitrogen was significantly improved. Besides, fluorescence tests have confirmed that highly conductive rGO can simultaneously capture or transfer photoelectrons within the system, thereby enhancing the photoelectron migration and reducing the private carrier recombination efficiency. N-rGO could act as an active electron accelerator, induce and enhance synergistic coupling, promote photocatalytic redox reactions, and dramatically improve the photocatalytic ability of modified graphene-based composite.