P. Romero-Gomez, C. Lopez-Santos, A. Borras, J.P. Espinos, A. Palmero, A.R. Gonzalez-Elipe
Chemical Physics Letters, 582 (2013) 95-99
doi: 10.1016/j.cplett.2013.07.025

This work reports the morphological and chemical modifications induced in TiO₂ thin films by bombardment with high energy N⁺ ions at different temperatures and their different photo-activity responses after implantation under visible and UV light illumination. When implanted samples are illuminated with visible light, no dye photo-decolouration takes place despite that light transformed the surfaces from hydrophobic to hydrophilic. In agreement with the Wenzel model of wetting, correlation is found between visible light photo-activity and film morphology. We conclude that the photo-activity response can be separated into shallow and Schottky barrier photo-activity, this latter involving a thicker layer of material.