We have deposited titanium dioxide TiO 2 thin films on glass using a single molecular precursor such as titanium (IV) isopropoxide ( Ti [ OCH ( CH 3)2]4, 97%) by sol–gel processing. Argon and oxygen rf plasma treatments at 295 K for 0.5 h in the power range of 50–200 W were also used to elevate photocatalytic activity of the as-grown TiO 2 films. A superhydrophilic property and surface morphology change appeared in the light irradiation with O 2 plasma treatment. In this work, the effect of the plasma with photocatalyst ( TiO 2) on the improvement of hydrophilic properties has mainly been investigated. Photocatalytic activity was evaluated by measurements of the uv/vis. irradiation, refractive index, contact angle, and AFM analysis. We confirmed that plasma treatment is a very reliable method for the synthesis of TiO 2 thin films with high catalytic performance.