AO treatment induced TiO 2 formation on the Ti surface and the crystal structure of TiO 2 varied with electrochemical conditions during AO. TiO 2 exhibits photocatalicity and superhydrophilicity, and it is used as an environmental photocatalyst for degrading toxic organic pollutants, bacteria and viruses absorbed on its surface under ultraviolet (UV) light illumination.
Source: wiktionary