Visible light driven degradation of methylene blue dye using Ag3PO4

Herein, we report the photocatalytic activity of Ag3PO4 under visible light irradiation with presence of methylene blue (MB) as target pollutant. The Ag3PO4 is prepared by ion-exchange and hydrothermal methods using water as solvent. The as-prepared Ag3PO4 is characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), Thermal gravimetric analysis (TG-DTA) and Impedance spectroscopy (IS). Finally, Ag3PO4 products were used as photocatalyst for the photodegradation of methylene blue in visible light irradiation. The various catalyst concentrations, such as 25, 50, 75 and 100 mg of Ag3PO4 are used to investigate the dye dependent degradation. The degradation results reveal that for all concentrations of Ag3PO4 prepared by ion-exchange synthesize method shows complete degradation with short irradiation time compared to hydrothermally prepared Ag3PO4. The reason behinds the ion-exchange Ag3PO4 exhibits low electrical resistivity which promotes more number of photogenerated electrons and holes plays major role in photodegradation of MB very faster. The photodegradation time of MB follows the order of 100 > 75 > 50 > 25 mg for both Ag3PO4 catalysts. Further the photodegradation mechanism of Ag3PO4 is also discussed in detail. (C) 2015 Elsevier Ltd. All rights reserved.