Advanced photocatalytic sterilization for recalcitrant Enterococcus sp. contaminated water by newly developed Z-scheme Bi2WO6 based composites under solar light. (January 2023) - Ming, Jie
Abstract: Pathogenic contamination is one of the major causes of clean water shortage, which poses great risk to human health. Herein, g-C3 N4 (CN) was firstly introduced to Ag/Ag2 O/BiPO4 /Bi2 WO6 (Ag/P/BWO) to construct a novel Z-scheme composite CN–Ag/P/BWO for disinfecting Enterococcus sp. contaminated water. CN–Ag/P/BWO showed excellent disinfection performance toward recalcitrant Enterococcus sp. under simulated solar light irradiation, achieving complete inactivation of 1.5 × 10 7 cfu mL −1 of bacterial cells only within 60 min, which was mainly attributed to the improved light absorption ability, charge carries separation/transfer efficiency and surface wettability. Additionally, the disinfection mechanism of CN–Ag/P/BWO toward Enterococcus sp. was systematically investigated. Photogenerated active species h +, ·OH and ·O2 − worked together and played crucial roles in photocatalytic inactivation. The antioxidant system enabled Enterococcus sp. self-protection ability at the beginning of disinfection through secreting more antioxidant enzymes. However, with accumulation of active species, bacterial cell membrane and energy system were damaged, which further led to leakage of intracellular components and decomposition of bacteria. Besides, CN–Ag/P/BWO exhibited high practicability for different environmental factors and also performed well for real lake water disinfection. The high stability further confirmed its practicability for water disinfection. This work not only systematically revealed the disinfection mechanism toward Enterococcus sp., but also provided an efficient method for water disinfection. Graphical abstract: Image 1 Highlights: Z-scheme CN–Ag/P/BWO was successfully constructed for water disinfection. CN–Ag/P/BWO exhibited enhanced optical capacity, fast charge separation and transfer. CN–Ag/P/BWO showed superior performance for Enterococcus sp. inactivation. Bactericidal mechanism toward Enterococcus sp. was systematically clarified. CN–Ag/P/BWO possessed high practicability for treating water contaminants.