Annealing Effects on Properties of Pure and Iron Doped Nano-TiO2 Films Prepared by Reactive Magnetron Sputtering

Pure and iron doped TiO₂ films were prepared by means of pulsed DC reactive magnetron sputtering method using pure and mixed titanium and iron targets. The TiO₂ films were deposited on microscope glass slides. The photocatalytic activity of the TiO₂ films was evaluated by measuring the degradation rate of aqueous methyl orange on the films under UV irradiation. Structure properties of the films and the effects on photocatalytic properties after annealing were investigated. The films were adhered on the substrates properly before annealing, whereas cracks appeared on the annealed films as well as weaker adhesion between the films and the substrates. The films were still in the anatase phase after annealing below 700°C, accompanied with apparently enhanced XRD peak intensity, which indicated crystalline growth during annealing process. Phase transformation from anatase to rutile occurred when the films were annealed above 800°C. Photocatalytic activities of the films dropped drastically alone with increasing annealing temperature.