Floating TiO2 photocatalyst for efficient inactivation of E. coli and decomposition of methylene blue solution.

The anatase phase TiO2 films with nanocrystalline structure were successfully deposited on a water-floating non-expanded polystyrene (PS) beads via magnetron sputtering. The combination of UVB light and PS beads with TiO2 film was used for decomposition of methylene blue as well as inactivation tests for intact and EDTA-treated Escherichia coli bacteria. Crystal structure, elemental composition, elemental mapping, surface morphology and chemical bonds of TiO2 film were investigated. E. coli inactivation experiments showed that such floating photocatalyst could destroy >90% bacteria in 45 min under UVB irradiation. Results demonstrated that combination of TiO2 and UVB light leads to disruption of the outer membrane which causes effective inactivation of E. coli bacteria.