Effect of inorganic ions, H2O2 and pH on the photocatalytic inactivation of Escherichia coli with silver impregnated combustion synthesized TiO2 catalyst

The photocatalytic antibacterial activity of Ag impregnated combustion synthesized TiO2 (0.25 g/L) was studied against Escherichia coli in presence of UV irradiation. The effect of various parameters, such as anions, cations, hydrogen peroxide and pH, on the photocatalytic inactivation was investigated. The addition of inorganic ions showed a negative effect on inactivation. Among anions, the presence of chloride ions was observed to have a maximum negative effect and reduced the inactivation considerably. Among cations, the bacterial inactivation reduced significantly in the presence of Ca2+ ions. Hydrogen peroxide addition in combination with Ag/TiO2 photocatalysis, however, improved the inactivation. Photocatalysis with high concentration of H2O2 yielded complete bacterial inactivation within few minutes. The photocatalytic inactivation of E. coli was not affected by variation in pH.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Effect of ions, H2O2 and pH on photocatalytic inactivation of Escherichia coli with Ag/TiO2. ► Addition of ions shows negative effect on the inactivation. ► H2O2 addition improves the inactivation of E. coli. ► The inactivation remains unaffected by variation in pH.