Electrostatically charged rutile TiO2 surfaces with enhanced photocatalytic activity for bacteria inactivation

In this work, the fabrication of a series of rutile-TiO 2 films with different submicron thicknesses supported on thermally grown SiO 2 is proposed. The aim is to determine the correlation between the generation of a positively charged TiO 2 surface, caused by the presence of dipoles formed at the TiO 2 /SiO 2 interface, with E. coli attraction. This electrostatic interaction leads to an improvement in the photocatalytic antibacterial activity. The positively charged TiO 2 surface formation was confirmed by Kelvin Probe Force Microscopy, E. coli adhesion tests, molecular docking, methylene blue, and methyl orange adsorption experiments. This effect on the photocatalytic surface of R-TiO 2 could favor the adsorption and degradation of negatively charged substances, as well as most of the pathogenic bacteria and viruses. • The fabrication of a series of rutile-TiO 2 films with different thicknesses on thermally grown SiO 2 was performed. • The generation of a positively charged TiO 2 surface caused by the presence of dipoles formed at the TiO 2 /SiO 2 was studied. • A correlation between the generation of a positively charged TiO 2 surface with E. coli attraction was determined. • KPFM, molecular docking E. coli and dyes adsorption experiments confirmed the formation of positively charged TiO 2 surface.