Preparation, characterization and photocatalytic properties of InVO 4 nanopowder and InVO4-TiO2 nanocomposite toward degradation of azo dyes and formaldehyde under visible light and ultrasonic irradiation

Abstract

In this study, photocatalytic activity of InVO4 and InVO 4-TiO2 nanoparticles in the degradation of aqueous solutions of industrial textile azo dyes such as Solophenyl Red 3BL, Coperoxon Nevy Blue RL and Black Nilusun 2BC (abbreviated as SR 3BL, CNB RL and BN 2BC, respectively) and also formaldehyde (abbreviated as FAD) under visible light and ultrasonic irradiations has been compared. The effect of various parameters such as pH, temperature, irradiation time, amounts of nanophotocatalyst and nanocomposite, and ultrasonic intensity on degradation rates was investigated. Then based on the Langmuir-Hinshelwood approach, reaction rates and adsorption equilibrium constants were calculated. The nanophotocatalyst and nanocomposite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis spectroscopic methods. It was observed that InVO 4-TiO2 nanopowder was more reactive than pure InVO 4 in the degradation of azo dyes under both conditions of visible light and ultrasonic irradiations. It was noticeable that degradation percent was more under ultrasonic irradiation rather than under visible light irradiation. © 2012 Iranian Chemical Society.