Characteristics and Photocatalytic Properties of Thin Film Prepared by Sputter Deposition and Post-N+Ion Implantation

Abstract

TiO2thin films of a rutile, an anatase, and a mixture type with anatase and rutile were fabricated by a magnetron sputtering method. The fabricated films were irradiated by N+ions with several doses using the Freeman ion source. Atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-VIS spectrophotometer were employed to investigate morphology, structure, chemical state, and optical characteristics, respectively. Photocatalytic activity was evaluated by degradation of a methylene blue solution using UV and visible light. TiO2thin films with each structure irradiated by N+ions showed the different N concentration in the same N+ion dose and the chemical state of XPS results suggested that an O atom in TiO2lattice replaced by an N atom. Therefore the photocatalytic activity of TiO2thin films was improved under visible light. The maximum photocatalytic activity of TiO2thin films with each structure was indicated at N concentration of 2.1% for a rutile type, of 1.0% for an anatase type, and of 3.8% for a mixture type under the condition of  ions/cm2in N+ion dose.