Abstract:

Photocatalytic nano-porous titanium dioxide films were prepared by the anodic oxidation method in sulfuric acid solution，and were loaded with silver by the photodeposition method.The microstructure and grain morphology in the films were characterized by SEM and XRD.The effect of anodizing parameters（anodizing voltage，current density and electrolyte concentration）on the photocatalytic bactericidal activity of TiO₂ films was investigated.It showed that the titanium oxide film was mainly composed of anatase and rutile TiO₂.With increasing anodizing voltage，the content of rutile TiO₂ increased，and the average diameters of nano-holes was enlarged.When the current density was 150 mA•cm^-2，the voltage increased from 120 V to 180 V，the content of rutile TiO₂ increased from 19% to 96%，the average diameters of nano-holes increased from 93 nm to 283 nm.A proper increase of current density and a suitable Ag loading could enhanced the photocatalytic activity of TiO₂ film.When prepared at 140 V/150 mA•cm^-2 in 1 mol•L^-1 sulfuric acid solution，and loaded with silver in 3 g•L^-1 silver nitrate solution，the Ag-TiO₂ film had the best photocatalytic bactericidal activity.The results suggested that photocatalytic bactericidal treatment with Ag-TiO₂ thin film has the potential for use as a new tool for water treatment.