Photocatalytic degradation of organic contaminants by TiO 2/sepiolite composites prepared at low temperature

Abstract

The TiO 2/sepiolite composites were successfully prepared by a facile and low-cost sol–gel technique at low temperature, using TiCl 4 as a precursor. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM), UV–vis diffuse reflectance spectrum (UV–vis DRS), N 2 adsorption–desorption and Fourier transform infrared (FT-IR) spectroscopy. The results showed that the ordered structure of sepiolite in the as-prepared samples was destroyed to some extent and the particle sizes of TiO 2 in the composites were less than 10 nm. The as-prepared samples showed an efficient photocatalytic activity for the degradation of acid red G (ARG) and 4-nitrophenol (4-NP) under UV light irradiation, which could be attributed to the synergetic effect of the large specific surface area of the TiO 2/sepiolite composites and the anatase phase of TiO 2 in it.