Efficient bacterial inactivation with S-doped g-C₃N₄ nanosheets under visible light irradiation

The pathogenic bacteria in water that threatens the human health and photocatalytic disinfection have been proven to be a cost-effective and promising green technology. It is significant and necessary to develop efficient, safe, and visible light-driven photocatalysts. In this study, Escherichia coli was used as model bacterium and the disinfection performance of prepared S-doped g-C₃N₄ nanosheets (S-CNNs) under visible light was investigated. The results showed that the synergistic effects of S doping and the unique 2D structure of S-CNNs enhanced the visible light absorption, enlarged the specific surface area and reduced the recombination of photogenerated charge carriers which is beneficial for promoting the photocatalytic disinfection of the E. coli. Scavenger experiments indicated •O₂^- and h⁺ were the predominant reactive species in the photocatalytic disinfection process. In addition, the kinetics of disinfection activity were fitted by the modified Hom model and the k₂ value of S-CNNs is 0.0219 min^-1, which is much higher than that of the bulk g-C₃N₄ (CN). This work has demonstrated efficient bacterial inactivation with S-CNNs under visible light irradiation.