N, S-doped Graphene Quantum Dots Grafted Graphitic Carbon Nitride to Boost its Photocatalytic Hydrogen Evolution and Antibacterial Activity

Abstract

Constructing heterojunction is one promising strategy to improve the transfer and separation of photoinduced charge carriers of graphitic carbon nitride (CN). Herein, nonmetal N, S-doped graphene quantum dots (N, S-GQDs)/g-C3N4 nanocomposite photocatalysts were successfully synthesized by calcining N, S-GQDs (NSGs) and melamine at elevated temperature. The optimal 06NSG-CN composite effectively reduced the concentration of Escherichia coli flora under visible light irradiation by superoxide and super hydroxyl radicals. Meanwhile, the optimum photocatalytic hydrogen evolution reaches 50.9 [Formula: see text]mol/h, about 16.9 times that of pure phase CN under visible light. Graphitic carbon nitride ([Formula: see text]-C3N4) grafted with N, S-doped GQDs could increase the specific surface area, promote the absorption and utilization of visible light, and inhibited the recombination of photoinduced electron–hole pairs, resulting in excellent photocatalytic antibacterial activity.