Pre-treating sputtered TiO2 film by photoelectrocatalysis to increase the performance of photo-activity and photoinduced hydrophilicity

We showed that the structure of TiO2 films prepared by magnetron sputtering underwent interesting change after photoelectrocatalysis (PEC) process. The analysis of field-emission scanning electron microscope revealed that the film morphology transform to interconnected porous structure after PEC treatment. Because the XRD and Raman analysis shows that the film crystallinity almost does not change after PEC treatment, we attribute the morphology change to the removing of amorphous TiO2 in the film. It was found that this structure change can effectively improve the photoelectrochemical response, and photocatalytic activity under UV light illumination. The post-treated TiO2 film also showed faster water wettability than that of pre-etched TiO2 film. The present research provides a simple and facile method to treat sputtered TiO2 film so as to improve its photochemical properties, which may be used as functional coatings of self-cleaning glasses.