Characteristics and Photocatalytic Activity of TiO<sub>2</sub> Films Immobilized on Ceramic, Glass and Stainless Steel

Abstract

To study the effects of substrate materials on the photocatalytic activity, TiO2films were immobilized on the inner wall surface of ceramic, glass and stainless steel tubes by sol-gel method. X-ray diffraction (XRD) results indicated that the crystal form of TiO2were all anatase type with theoretical particle size of 15 nm. According to the X-ray photoelectron spectroscopy (XPS) results, appearance of the element Na was observed which would decrease the photocatalytic activity. Scanning electron microscope (SEM) photos showed that the film coating on the ceramic and glass were even and uniform with thickness of about 300 nm and practical particle size of 20 nm to 100 nm. However, the film coating on stainless steel was hackly which would lead to diffraction of lights. The degradation rate constants of methylene blue (MB) with initial concentration of 5 mg.L-1were 0.049 min-1、0.029 min-1and 0.023 min-1with films coating on ceramic, stainless steel and glass tubes respectively. Degraded with TiO2film coating on ceramic tube, the according rate constants of phenol were 0.37, 0.14, 0.04 and 0.02 min-1for initial concentration of 2, 10, 50 and 100 mg.L-1respectively.