Estudo da atividade fotocatalítica dos nanocompósitos TiO2- x%CeO2 e CeO2-x%TiO2 obtido pelo método hidrotérmico assistido por micro-ondas

Abstract

The accelerated industrial growth allied to the expansion of agriculture has been causing concern with the generation of polluting effluents, being their methods of treatment, the target of several studies to mitigate investigate the damage caused by such waste. A widely studied method is the Advanced Oxidation Process (AOP), which aims for the treatment of organic effluents. In this work, nanocomposites were obtained from titanium oxide and cerium oxide, forming compounds CeO2-x%TiO2 and TiO2- x%CeO2, varying x = 10, 30 and 50 mol%. The nanocomposites were synthesized by the microwave assisted hydrothermal method, with subsequent calcination at 500 °C, with the aim of investigating the photocatalytic activity through the degradation of methylene blue dye under UV radiation, commonly used in the textile industry. The compounds were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), surface area analyzed by the BET method (Brunauer, Emmett, Teller) and UV-Vis spectroscopy (UV-Vis). The XRD results showed formation of TiO2 and CeO2 phases, with no indication of chemical interaction between the two compounds. By the Scherrer method and with the XRD results, was observed oxides’ molar ratio influences on the crystallite sizes. Morphologies of nanocubes and nanospheres with different levels of agglomeration and average particle size varying from 2 to 24 nm were observed, as well as a specific surface area ranging from 20.24 m2 /g to 62.80 m2 /g. For the nanocomposite using CeO2-x% TiO2, the compounds with x = 50 mol% presented better photocatalytic activities, with degradation of approximately 80% of the dye. From the compounds with TiO2 as the matrix, the TiO2- x%CeO2 nanocomposite with x = 10% degrading the entire dye.