Modulating nanograin size and oxygen vacancy of porous ZnO nanosheets by highly concentrated Fe‐doping effect for durable visible photocatalytic disinfection

Abstract

Abstract Visible light‐driven environmentally friendly ZnO semiconductor for durable photocatalytic disinfection and purification of drinking water is very promising. However, the high requirement in ultraviolet absorption and rapid recombination velocity of the photogenerated electron‐hole severely hamper the sustainable implementation of ZnO in photocatalysis. Herein, by one “two birds with one stone” strategy, Fe‐doping ZnO porous nanosheets (Fe‐ZnOPN) composed of ultrafine nanoparticles can be constructed by hydrothermal synthesis of basic zinc carbonate and controlled low‐temperature pyrolytic methods. By highly concentrated Fe‐doping effect (> 7 wt%), the tailoring ZnO nanograin size (~10 nm) and rich oxygen vacancy of catalyst were accessed by ion/vacancy diffusion and nanocrystal rearrangement, superior to the ZnO porous nanosheets (~37 nm). The obtained Fe‐ZnOPN were endowed with a larger specific surface area, improved visible light harvesting ability, light response and separation of charge carriers. Such characters allowed the resulting catalyst to afford a 100% bactericidal efficiency against Pseudomonas aeruginosa and Staphylococcus aureus under visible light irradiation (> 420 nm). Impressively, the Fe‐ZnOPN could show practical disinfection ability in different water resources and multiple reuse ability. The mechanism study revealed that excellent photocatalytic disinfection performance of Fe‐ZnOPN correlated with the in situ generated active oxidative substances, destruction of bacterial biofilm and resulting nucleic acids leakage, thereby causing irreversible physical damage. This study provided a new reference for designing environmentally friendly photocatalytic sterilization materials and disinfectants, which can be used in the practical disinfection of drinking water.