Glancing Angle Sputter Deposition of Titanium Dioxide Films for Photocatalytic Applications

Here, the nanostructure of TiO2 photocatalytic films was controlled for photocatalytic applications using glancing angle sputter deposition and oxygen-ion-assisted reactive evaporation (OARE). The grain size and surface asperity both increase as the deposition angle increases, and films with high porosity were obtained at high incidence angles. However, the film deposited using sputtering has a much larger column diameter and a denser structure than the film deposited using OARE. Therefore, the film deposited using glancing angle sputter deposition at an incidence angle of 80° had much better photocatalytic properties than the film deposited using OARE: it was superhydrophilic after 1 h of UV irradiation and showed excellent organic decomposition performance. An increase in the porosity of this film led to a significant increase in its UV absorptance, which also improved its photocatalytic performance. In particular, the film deposited at 80° using sputtering had a UV absorptance above 70%.