Preparation of TiO₂/Activated Carbon Composites for Photocatalytic Degradation of RhB under UV Light Irradiation

Abstract

Photocatalysts comprising nanosized TiO 2 particles on activated carbon (AC) were prepared by a sol-gel method. The TiO 2 /AC composites were characterized by X-ray diffraction (XRD), thermogravimetric (TG) analysis, nitrogen adsorption, scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive X-ray (EDX). Their photocatalytic activities were studied through the degradation of Rhodamine B (RhB) in photocatalytic reactor at room temperature under ultraviolet (UV) light irradiation and the effect of loading cycles of TiO 2 on the structural properties and photocatalytic activity of TiO 2 /AC composites was also investigated. The results indicate that the anatase TiO 2 particles with a crystal size of 10–20 nm can be deposited homogeneously on the AC surface under calcination at 500°C. The loading cycle plays an important role in controlling the loading amount of TiO 2 and morphological structure and photocatalytic activity of TiO 2 /AC composites. The porosity parameters of these composite photocatalysts such as specific surface area and total pore volume decrease whereas the loading amount of TiO 2 increases. The TiO 2 /AC composite synthesized at 2 loading cycles exhibits a high photocatalytic activity in terms of the loading amount of TiO 2 and as high as 93.2% removal rate for RhB from the 400 mL solution at initial concentration of 2 × 10 −5 mol/L under UV light irradiation.