Surface properties of photocatalytic TiO₂ thin films with microwave discharged plasma surface treatment

We have deposited titanium dioxide (TiO₂) thin films on glass using a single molecular precursor such as titanium (IV) iso-propoxide (Ti[OCH(CH₃)₂] 4, 97 %) by sol-gel process. In order to elevate photocatalytic activity of the as-grown TiO₂ films, argon and oxygen plasmas ignited by microwave (MW) discharge at 300 W under vacuum condition were also used within 5 min. at room temperature. Photocatalytic activity was evaluated by the measurements of the contact angle, FT-IR, XPS, and AFM analysis. In this work, the effect of the plasma on the improvement of hydrophilic property of TiO₂ photocatalyst has mainly been investigated. Superhydrophilic property and smooth surface morphology appeared in the UV light irradiation with O₂ plasma treatment more than Argon plasma treatment. Based on this work, we confirmed that the oxygen MW plasma treatment method was very reliable method for the synthesis of TiO₂ thin films with high catalytic performance.