Síntese e caracterização de óxidos de titânio (IV) puro e dopado com zircônio para aplicação tecnológica em fotocatálise heterogênea

Abstract

In this work two different materials were prepared through polymeric precursors synthesis, titanium dioxide and titanium dioxide doped with zirconium. In addition to the synthesis and characterization of these materials, the objective of this work was to apply these oxides in heterogeneous photocatalysis to demonstrate the photocatalytic characteristics of both materials in the degradation reaction of the methylene blue dye. The resulting materials were characterized using ATG-DTG-DTA, DRX and MEV spectroscopy techniques. The different processes performed were important in the development of this work. Through the (ATG-DTG-DTA) analysis the phase transitions of the samples were identified and the best calcination temperatures of the materials were determined. This allowed the obtaining of the desired crystalline phases. The DRX analysis of the synthesized samples presented two distinct phases, anatase and rutile, with varying proportions between the temperatures of 400 ºC and 700 ºC. The MEV technique allowed the observation of the morphology of the material. The oxides presented agglomeration of particles in the form of irregular heterogeneous plates. Using the technique of UV-vis it was possible to quantify the concentrations of the methylene blue dye solutions submitted to the heterogeneous photocatalysis degradation process, using as catalysts the materials obtained in the present study, in order to evaluate the possible photocatalytic activity of the same. The results were expressed in absorbance as a function of the reaction time. The materials obtained by the polymeric precursors method were compared with the TiO2 commercial P25 catalyst, and both showed good results as catalysts for heterogeneous photocatalysis, promoting the degradation of much of the dye contained in solution.