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 TiO ₂-MV was investigated for the degradation of fast green (FG) dye under visible light irradiation. The photocatalytic activity of TiO ₂-silver vanadate [TiO₂-Ag₃VO₄] was found to be much higher than that of TiO₂-cadmium vanadate [TiO ₂-CdV₂O₆], TiO₂-strontium vanadate [TiO₂-Sr₃(VO₄)₂] and TiO ₂. 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, TiO ₂-Ag₃VO₄ was found to be a reusable photocatalyst.