Estudo de Nanopartículas de TiO2 dopadas com V: Avaliação da Eficiência Catalítica

Abstract

Currently, many researchers aim to contribute to the development of new technologies that are harmonic with the environment, ecologically clean, safe and sustainable. The degradation of organic contaminants by catalytic process, which uses reactions of doped semiconductors with high surface area that interacts with adsorbate. Among the semiconductor oxides, titanium dioxide (TiO2) has been the most studied catalyst used for the degradation of different dyes. However, due a great limitation of TiO2 as catalyst in order to oxides dyes another ways may be used to improve their efficiency. Thus, the search for new materials that present a good catalytic activity to adsorb and degrade contaminants is increasing. In this context, this work aimed to prepare nanostructures of TiO2 doped with different concentrations of vanadium (V), To study their structural, vibrational, optical and electronic properties and, consequently, their efficiency in the degradation processes of organic dyes. The TiO2 nanostructures, which were prepared using the polymeric precursor method, were doped with the following theoretical concentrations of V respect to the Ti: 0.0% (pure sample), 0.2%, 0.5%, 1.0%, 2.0% and 3.0%. The characterization was carried out through X-ray diffraction (XRD), Raman scattering, scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy (EDX), and X-ray excited photoelectron spectroscopy (XPS) measurements. Adsorption tests (in the dark) of the methylene blue dye were carried out and where found that the increase in the incorporated V concentration promotes a significant increase in the adsorption of MB by the nanoparticles. At the same time, the increase of the V concentration promotes a decrease in the catalytic efficiency of the nanoparticles.