Stability of the Photocatalytic Activity of TiO 2 Deposited by Reactive Sputtering

Abstract The photocatalytic activity and stability of TiO2 thin films deposited by reactive sputtering were evaluated through many cycles of aqueous methylene blue solutions photodegradation. Tests were performed in TiO2 films deposited onto silica, silicon, and lanthanum aluminate substrates under UV light irradiation. The dye degradation was determined using the optical absorbance spectra at pre-established exposure times. After 16 cycles of reaction, 180 minutes each, no systematic losses in the photocatalytic activity were observed in the samples. The best activity was observed on films deposited onto silica glass. The results indicate that the TiO2 samples deposited by the sputtering technique are stable concerning the UV degradation of methylene blue.