Visible-Light-Driven Photocatalytic Water Disinfection Toward Escherichia coli by Nanowired g-C3N4 Film

Yizhu Zhang,Jian Liu,Shigang Su,Xiaohua Huang,Paolo Giusto,Xia Zhang,Yuanyuan Zhang

doi:10.3389/fnano.2021.684788

Abstract

Graphitic carbon nitride (g-C3N4) as metal-free visible light photocatalyst has recently emerged as a promising candidate for water disinfection. Herein, a nanowire-rich superhydrophilic g-C3N4 film was prepared by a vapor-assisted confined deposition method. With a disinfection efficiency of over 99.99% in 4 h under visible light irradiation, this nanowire-rich g-C3N4 film was found to perform better than conventional g-C3N4 film. Control experiments showed that the disinfection performance of the g-C3N4 film reduced significantly after hydrophobic treatment. The potential disinfection mechanism was investigated through scavenger-quenching experiments, which indicate that H2O2 was the main active specie and played an important role in bacteria inactivation. Due to the metal-free composition and excellent performance, photocatalytic disinfection by nanowire-rich g-C3N4 film would be a promising and cost-effective way for safe drinking water production.

Highlights

The COVID-19 pandemic has demonstrated the critical importance of sanitation, hygiene and adequate access to clean water for preventing and containing diseases
Either melamine or urea was employed as precursor alone for synthesizing the g-C3N4 film and the optical images were shown in Supplementary Figure S2
Only few works report on the wettability of g-C3N4 film, which is an important parameter for water disinfection (Liang et al, 2015; Lin et al, 2019; Wu et al, 2019; Giusto et al, 2020c)

Summary

Introduction

The COVID-19 pandemic has demonstrated the critical importance of sanitation, hygiene and adequate access to clean water for preventing and containing diseases. A simple vapor-assisted confined deposition method was performed to obtain the nanowire-rich and superhydrophilic g-C3N4 films as previously reported (Jia et al, 2019). In a typical synthesis of such nanowire-rich g-C3N4 film on the ground glass substrate, the mixture of urea and melamine was employed as precursor for thermal polycondensation in a vapor-assisted confined deposition setup.

Results

Conclusion