Decolorization of C.I. Reactive Red 2 by UV/TiO2/PAC and visible light/TiO2/PAC systems

Abstract

AbstractIn this work, the sol-gel method is utilized to synthesize TiO2/powder-activated carbon (PAC) from TiCl4 and PAC. The TiO2/PAC system was used to decolorize C.I. Reactive Red 2 (RR2) under ultraviolet (UV) and visible light irradiation. The surface characteristics of TiO2 and TiO2/PAC were analyzed by X-ray diffractometer, scanning electron microscopy, transmission electron microscopy, UV-vis spectroscopy, BET surface area analysis, and X-ray photoelectron spectroscopy (XPS). The effects of the C/Ti ratio, calcination temperature, photocatalyst dose, RR2 concentration, wavelength of light, and pH on the decolorization of RR2 by TiO2/PAC were evaluated. The optimal calcination temperature for forming TiO2 and TiO2/PAC was 400°C; moreover, the surface areas of TiO2 and TiO2/PAC were 42 and 108 m2/g, respectively. The sizes of the aggregates of TiO2 and TiO2/PAC particles were approximately 40 and 30 nm, respectively. Experimental results reveal that the percentage of anatase increased with the amoun...