Synthesis and characterization of nanostructured ceria-titania for photocatalytic applications

Abstract

The purpose of following thesis is synthesizing nanostructured TiO2 samples using hydrothermal method containing different CeO2 loadings ranging from 0.1 to 5.0 wt% and investigating their photocatalytic activity. Prepared samples characterized by different techniques to analyze them. Textural and structural characterization (surface and bulk properties) by using X-ray diffraction, the surface area and pore size distribution of synthesized samples were calculated by N₂ physisorption. morphological characterization and optical characterization, the size, shape and composition of synthesized nanoparticles were characterized by high resolution transmission electron microscopy (HRTEM) and energy dispersive x-ray (EDX) and optical properties were investigated by measuring their band gap energy (Eg ). Figure shows the change in diffuse reflectance optical spectra with increased ceria doping. To evaluate the synthesized photocatalysts, the degradation of two industrial dyes, methylene blue (MB) and methylene orange (MO) were chosen as a test reaction in aqueous suspension under light irradiation at room temperature and atmospheric pressure. Under UV light the CeO2-TiO2 nanostructured photocatalysis were found active in the reaction, obtain high degradation values after the monitored reaction period (120 min), with all CeO2-containing nanomaterials exhibit a degradation rate higher that that of pure TiO2 samples. The most promising materials, displaying a convenient energy gap value, were also tested in the same operating conditions under simulated solar light irradiation. The conclusion of the test experiment confirmed that the amount of ceria in the bodywork of titania and undoubtedly lowering the band gap to match with visible light absorption, can elevate the photocatalytic activity. Eventually, Ce-containing nanoparticles synthesized by a hydrothermal approach, demonstrate a higher rate of photodegradation than that of pure titania samples.