A Novel Visible– Light Driven Photocatalyst: Ethylene Glycol–Citrate Sol–Gel Synthesis, Microwave–Assisted Calcination, and Photocatalytic Efficiency

Abstract

A novel visible– light driven photocatalyst, BIMNVOX.x was synthesized by ethylene glycol–citrate sol–gel route and microwave- assisted calcination. The phocatalyst was characterized structurally by X–ray powder diffraction (XRPD) and simultaneous thermogravimetric–differential thermal analysis (TG–DTA). Its optical and surface properties were determined by means of UV–vis absorption spectrophotometry and BET– nitrogen adsorption isotherm measurements, respectively. The photocatalytic efficiency of BIMNVOX.x system was investigated by applying the pseudo first- order kinetic model to the photocatalytic degradation reaction of crystal violet, CV dye in aqueous solution under visible light irradiation. The β (orthorhombic) –BIMNVOX phase, space group Acam exhibited the highest photocatalytic degradability, indicating that the photocatalytic efficiency of BIMNVOX catalyst is essentially enhanced by the increased number of catalyst active sites, irrespective of the kind of phase stabilized and the increasing photoabsorption ability with Mn dopant content. Moreover, the possible photocatalytic degradation mechanism of aqueous CV dye solution under visible light irradiation was also proposed.