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

• Published in: Applied surface science Vol. 311; pp. 369 - 376
• Main Authors: Sun, Qing, Li, Hui, Zheng, Shuilin, Sun, Zhiming
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30-08-2014; Elsevier
• Subjects: Chromium; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cr (VI); Cross-disciplinary physics: materials science; rheology; Diatomite; Exact sciences and technology; Photocatalysis; Physics; Reduction; Scanning electron microscopy; Surface chemistry; TiO2; Titanium dioxide; X-rays; Diatomite; Photocatalysis; Cr (VI); TiO2; Inorganic compounds; Transition element compounds; TiO; Titanium oxide; Nanostructured materials
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2014.05.070

Nano-TiO2/diatomite (DIA) composites were successfully synthesized by a typical hydrolysis precipitation method. The composites show good photocatalytic activity and stability for aqueous Cr (VI) removal.
•TiO2 nanoparticles/diatomite composite was synthesized and characterized.•The composite exhibited a good photocatalytic performance in Cr (VI) reduction.•The photocatalyst showed good photocatalytic stability.•The composite is a promising material for Cr (VI) photocatalytic reduction.
In this paper, the TiO2 nanoparticles were immobilized on diatomite (DIA) via a typical hydrolysis precipitation process using TiCl4 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). TiO2 nanoparticles with the average grain size of around 7–14nm 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 TiO2 (P25, Degussa), the TiO2/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.