Visible light assisted photocatalytic activity of TiO2-metal vanadate (M=Sr, Ag and Cd) nanocomposites

TiO2-metal vanadate nanocomposites (TiO2-MV) were synthesized by the precipitation method and successfully characterized using UV-visible diffuse reflectance spectroscopy (UV-vis-DRS), powder X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) techniques. The photocatalytic activity of TiO2-MV was investigated for the degradation of fast green (FG) dye under visible light irradiation. The photocatalytic activity of TiO2-silver vanadate [TiO2-Ag3VO4] was found to be much higher than that of TiO2-cadmium vanadate [TiO2-CdV2O6], TiO2-strontium vanadate [TiO2-Sr3(VO4)2] and TiO2. The effect of operational parameters such as pH, photocatalyst concentration and initial dye concentration on the photodegradation of FG was examined in detail. The mineralization of FG was confirmed by chemical oxygen demand (COD) and total organic carbon (TOC) measurements. Moreover, TiO2-Ag3VO4 was found to be a reusable photocatalyst.