Photocatalytic inactivation of E. coli with a mesoporous TiO2 coated film using the film adhesion method.

The photocatalytic inactivation of Escherichia coli with the film adhesion method by using Degussa P25TiO2 and mesoporous TiO2 coated on glass was investigated. Monodisperse spherical mesoporous TiO2 with a morphology size of approximately 800 nm was synthesized via the sol-gel approach and coated onto glass substrates without cracking by using the doctor blade method with various amounts of polyethylene oxide (PEO) and polyethylene glycol (PEG). Photocatalytic disinfection was tested by varying the UV-A light intensity, cell concentration, and UV-A irradiation time. The photocatalytic inactivation achieved with mesoporous TiO2 was found to be higher than that with the commercial P25TiO2. Byvarying the surface area and crystallite size of mesoporous TiO2 through control of the calcination temperature, we found that the efficacy of photocatalytic disinfection with the film adhesion method is strongly dependent on the surface area and crystallite size: the larger the surface area and the smaller the crystallites, the higher the efficacy of photocatalytic inactivation.