Photocatalytic disinfection of E. coli using N-doped TiO_2 composite

摘要

Heterogeneous photocatalysis is among an alternative technique for the inactivation of pathogenic microorganisms. Several researchers have achieved the successful killing of bacteria, viruses, fungi or protozoa by semiconductor photocatalysis. This study significantally provides a better understanding of the bactericidal properties of N-TiO_2 by identifying specific bacterial targets and cell strcuture during disinfection in pure water. The photocatalytic inactivation of bacteria was investigated using E. coli, a well-known bacterial indicator. Firstly, the effects of the contact of N-doped TiO_2 with bacterial cells in the dark on both the bacterial cultivability and the envelope integrity was carried out. Then, assessment of the deleterious effects of N-doped TiO_2 on the bacteria's permeability and cultivability was done under visible radiations exposure. In order to identify the cell structure during the inactivation of the bacteria, monitoring of atomic force microscopy was also carried out.