Visible-Light Photocatalysis in Ca0.6Ho0.4MnO3 Films Deposited by RF-Magnetron Sputtering Using Nanosized Powder Compacted Target

A novel immobilized Ca0.6Ho0.4MnO3 photocatalyst has been developed with high photocatalytic activity for Rhodamine 6G (Rh6G) photodegradation under visible light irradiation. The nanocrystalline Ca0.6Ho0.4MnO3 films were successfully deposited by RF-magnetron sputtering on unheated quartz glass substrates using Ca0.6Ho0.4MnO3 powder as sputtering target and its photocatalytic functionalities have been explored. The visible-light-responsive photocatalytic activity of Ca0.6Ho0.4MnO3 films was evaluated by the photodegradation of Rh6G aqueous solutions under visible light irradiation. The reusability of Ca0.6Ho0.4MnO3 films on fresh dye samples was studied, showing an efficient reuse, without decreasing the photocatalytic decolorization efficiency. Furthermore, X-ray diffraction of the reused films did not reveal additional phases indicating high photochemical stability of the films even after reusing them in successive runs. The photocatalytic efficiency of the nanocrystalline Ca0.6Ho0.4MnO3 films was further compared with TiO2 films also produced by sputtering and the results revealed a significant improvement in photocatalytic activity over TiO2 under visible light irradiation. Almost complete photodecolorization of a 5 ppm Rh6G solution was achieved in 4 h, while only 64% of dye degradation was observed in TiO2 photoassisted process. This work provides a feasible route to fabricate high-performance immobilized ABO(3)-based nanomaterials, and the finding opens up a new venue for designing visible light sensitive ternary compounds for photocatalytical applications.