OICC Press Journal of Nanostructure in Chemistry 2193-8865 5 1 (March 2015) 2014 10 02 Synthesis, characterization, and application of Nd, Zr–TiO2/SiO2 nanocomposite thin films as visible light active photocatalyst 10.1007/s40097-014-0123-0 EN Susan Samadi Department of Chemistry, College of Basic Science, Yadegar-e-Imam Khomeini (RAH) Branch, Islamic Azad University, Tehran, IR Mohammad Yousefi Department of Chemistry, College of Basic Science, Yadegar-e-Imam Khomeini (RAH) Branch, Islamic Azad University, Tehran, IR Faezeh Khalilian Department of Chemistry, College of Basic Science, Yadegar-e-Imam Khomeini (RAH) Branch, Islamic Azad University, Tehran, IR Ameneh Tabatabaee Department of Chemistry, College of Basic Science, Yadegar-e-Imam Khomeini (RAH) Branch, Islamic Azad University, Tehran, IR Journal Article 2014 10 02 Abstract A novel Nd, Zr–TiO 2 /SiO 2 nanocomposite thin film was successfully prepared with various amounts of Nd 3+ and Zr 4+ as codopant ions for self-cleaning applications. In the first step, two types of Zr, Nd–TiO 2 /SiO 2 thin films were prepared using ZrCl 4 and ZrOCl 2 compounds as a source of second doping agent ions. The result of the scanning electron microscopy (SEM) indicated that ZrOCl 2 precursor produces a more monotonous thin film, but study of the photocatalytic activity of these thin films showed that ZrCl 4 -based thin film possess a more significant photocatalytic activity. Based on these results, ZrCl 4 was chosen as a source of doping ion. Two kinds of Nd, Zr–TiO 2 /SiO 2 nanocomposite thin films A and B were synthesized using various techniques. Type A thin film was coated on a glass substrate by heat treatment, but Type B was coated on polycarbonate sheets without any heat treatment process. The SEM images and XRD pattern showed that the optimum amount of doping ion in relation to Ti 3+ is 0.1 %. In this circumstance, the most monotony of film was seen and the main formed phase was anatase. The sample structures were characterized by infrared spectroscopy. The nanocomposite films were found to be active for photocatalytic decomposition of methyl orange as an organic pollutant.