Multilayered TiO2/TiO2−x/TiO2 films deposited by reactive sputtering for photocatalytic applications

Abstract

Multilayered TiO2/TiO2−x/TiO2 films, deposited by twenty periodical interruptions of O2 flow during reactive sputtering deposition were submitted to photocatalytic tests and characterized. The O2 flow interruptions lasted 10 s, 38 s, 45 s, and 70 s, while the regular flow periods lasted 540 s. The photocatalytic tests were performed using UV irradiation from a mercury lamp and a solution of methylene blue dye. The best photocatalytic response was observed in samples corresponding to 10 s interruptions. The results show that the amount of degraded dye was increased by an average of 1.67 times in the interrupted flow sample as compared to the homogeneous TiO2 film deposited under similar conditions. The results show that this relatively simple deposition procedure can produce significant improvements to the photocatalytic activity of the TiO2-based catalysts. Graphic abstract: [Figure not available: see fulltext.]