Influence of sputtering power on structure and photocatalyst properties of DC magnetron sputtered TiO2 thin film

TiO2 thin films were deposited by DC reactive magnetron sputtering technique on silicon wafer and glass slide at sputtering power of 210 W and 230 W. A pure metallic titanium target was sputtered in a mixture of argon and oxygen gases. The distance of Ti-target to substrate holder (ds-t) was 120 mm. The films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. The photocatalytic activity was evaluated by the measurement of the decomposition of methylene blue after UV irradiation. It was found that the crystalline structure of TiO2 thin films strongly depended on the sputtering power. The mixed phase of anatas/rutile TiO2 thin films were successfully obtained with the sputtering power of 230 W. While anatase TiO2 thin films were obtained with sputtering power of 210 W. The TiO2 thin film with anatase structure exhibited the best photocatalytic activity.