Preparation of Ce–TiO 2 catalysts by controlled hydrolysis of titanium alkoxide based on esterification reaction and study on its photocatalytic activity

Abstract

The Ce–TiO 2 catalysts were prepared by controlled hydrolysis of Ti(OC 4H 9) 4 with water generated “in situ” via an esterification reaction between acetic acid and ethanol, followed by hydrothermal treatment. The samples were characterized by X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), atomic absorption flame emission spectroscopy (AAS), and nitrogen adsorption–desorption methods. Both of undoped TiO 2 and Ce–TiO 2 samples exclusively consist of primary anatase crystallites, which further form spherical aggregates with diameters ranging from 100 to 500 nm. The photocatalytic activity of Ce–TiO 2 was investigated for the photocatalytic degradation of Rhodamine B (RB) aqueous solution both under UV and visible light irradiation. Doping of Ce 4+ effectively improves the photocatalytic activity under both UV light irradiation and visible light irradiation with an optimal doping concentration of 0.2 and 0.4%, respectively. The photocatalytic mechanisms of Ce–TiO 2 catalysts were tentatively discussed.