title: Enhanced visible-light-driven photocatalytic inactivation of Escherichia coli using g-C3N4/TiO2 hybrid photocatalyst synthesized using a hydrothermal-calcination approach.
abstract: Biohazards are widely present in wastewater, and contaminated water can arouse various waterborne diseases. Therefore, effectively removing biohazards from water is a worldwide need. In this study, a novel visible-light-driven (VLD) graphitic carbon nitride (g-C3N4)/TiO2 hybrid photocatalyst with high photocatalytic bacterial inactivation activity was successfully synthesized using a facile hydrothermal-calcination approach. The optimum synthesized hybrid photocatalyst is composed of micron-sized TiO2 spheres (average diameter: ca. 2 μm) and wrapped with lamellar g-C3N4 (thickness: ca. 2 nm), with narrowing bandgap (ca. 2.48 eV), leading to a significant improvement of visible light (VL) absorption and effective separation of photo-generated electron-hole pairs. This greatly enhances VL photocatalytic inactivation activity towards bacteria in water. Using this hybrid photocatalyst, 10(7) cfu mL(-1) of Escherichia coli K-12 could be completely inactivated within 180 min under VL irradiation. SEM images indicate that bacterial cells were greatly damaged, leading to a severe leakage of intracellular components during photocatalytic inactivation processes. The study concludes that bacterial cell destruction and water disinfection can be achieved using this newly fabricated VLD hybrid photocatalyst.
authors.affiliation: State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Guiying
authors.initials: G
authors.lastname: Li
authors.affiliation: State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Nie
authors.affiliation: State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Jiangyao
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address: antc99@gig.ac.cn.
authors.forename: Taicheng
authors.initials: T
authors.lastname: An
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China.
authors.forename: Po Keung
authors.initials: PK
authors.lastname: Wong
authors.affiliation: Centre for Clean Environment and Energy, Griffith University, Gold Coast Campus, QLD, 4222, Australia.
authors.forename: Haimin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Centre for Clean Environment and Energy, Griffith University, Gold Coast Campus, QLD, 4222, Australia.
authors.forename: Huijun
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Yamashita
mesh_terms: D002384:Catalysis; D004203:Disinfection / Q000379:methods*; D048168:Escherichia coli K12 / Q000528:radiation effects* / Q000648:ultrastructure; D008027:Light; D008855:Microscopy, Electron, Scanning; D009570:Nitriles / Q000737:chemistry; D055668:Photochemical Processes; D014025:Titanium / Q000737:chemistry*; D062065:Wastewater / Q000382:microbiology
chemical_list: D009570:Nitriles; D014025:Titanium; D062065:Wastewater; C009495:titanium dioxide; C011206:cyanogen
keywords: Escherichia coli K-12; Photocatalytic inactivation; Visible light irradiation; Water disinfection; g-C(3)N(4)/TiO(2)