Photocatalytic degradation of pathogenic bacteria with AgI/TiO2 under visible light irradiation.
The photocatalytic disinfection of pathogenic bacteria in water was investigated systematically with AgI/TiO2 under visible light (lambda > 420 nm) irradiation. The catalyst was found to be highly effective in killing Escherichia coli and Staphylococcus aureus. The adsorbed *OH and hVB+ on the surface of the catalyst were proposed to be the main active oxygen species by study of electron spin resonance and the effect of radical scavengers. The process of destruction of the cell wall and the cell membrane was verified by TEM, potassium ion leakage, lipid peroxidation, and FT-IR measurements. Some products from photocatalytic degradation of bacteria such as aldehydes, ketones, and carboxylic acids were identified by FT-IR spectroscopy. These results suggested that the photocatalytic degradation of the cell structure caused the cell death. The electrostatic force interaction of the bacteria-catalyst significantly affected the efficiency of disinfection on the basis of the E. coli inactivation under different conditions.
Hu
Chun
C
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Guo
Jian
J
Qu
Jiuhui
J
Hu
Xuexiang
X
D000327:Adsorption; D002384:Catalysis; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D007454:Iodides / Q000737:chemistry* / Q000494:pharmacology; D008027:Light; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission / Q000379:methods; D010084:Oxidation-Reduction; D010316:Particle Size; D010777:Photochemistry; D011188:Potassium / Q000378:metabolism / Q000528:radiation effects; D012680:Sensitivity and Specificity; D018030:Silver Compounds / Q000737:chemistry* / Q000494:pharmacology; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013211:Staphylococcus aureus / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology
D007454:Iodides; D018030:Silver Compounds; C009495:titanium dioxide; D008315:Malondialdehyde; C030584:silver iodide; D014025:Titanium; D011188:Potassium