Plasma surface modification of TiO2 photocatalysts for improvement of catalytic efficiency

We have deposited titanium dioxide (TiO2) thin films on glass using titanium (IV) isopropoxide (Ti[OCH(CH3)2]4, 97%) by sol–gel processing. In order to elevate photocatalytic activity of the as-grown TiO2 films, argon and oxygen plasmas ignited by radio-frequency (RF) and microwave (MW) under both vacuum and atmosphere conditions were also used in the range of 50–200 W within 30 min at room temperature. Photocatalytic activity was evaluated by the measurements of the contact angle, UV/vis irradiation, and toluene removal test. In this work, the effect of the plasma with photocatalyst (TiO2) on the improvement of hydrophilic properties has mainly been investigated. A superhydrophilic property and surface morphology change appeared in the light irradiation with O2 plasma treatment. Based on this work, we confirmed that the plasma treatment method was very reliable method for the synthesis of TiO2 thin films with high catalytic performance.