Characterizations of nano-TiO2/diatomite composites and their photocatalytic reduction of aqueous Cr (VI)

Abstract

Abstract In this paper, the TiO 2 nanoparticles were immobilized on diatomite (DIA) via a typical hydrolysis precipitation process using TiCl 4 as precursor. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). TiO 2 nanoparticles with the average grain size of around 7–14 nm were well deposited on the surface of diatomite. The photocatalytic activity toward the reduction of aqueous Cr (VI) was demonstrated under UV light. The influence of initial pH values, catalyst amount, illumination intensity and initial concentration of Cr (VI) on photocatalytic reduction of Cr (VI) were investigated. Compared with the commercial TiO 2 (P25, Degussa), the TiO 2 /DIA composites had better reactive activity because of their relatively higher adsorption capacity. Furthermore, the prepared photocatalyst exhibited relatively good photocatalytic stability depending on the reusability tests.