Estudo da atividade fotocatalítica e fotoluminescente do titanato de zinco dopado com európio sintetizado pelo método dos precursores poliméricos

Abstract

In recent years ceramic materials have been studied and are evolving rapidly, mainly the advanced ceramics. The various properties involving these materials, such as photoluminescence and photocatalysis justify the increasing need for better understanding of the influence of the addition of doping in the final properties. In this work the polymeric precursor method was used to obtain Zn2TiO4 doped with Eu3+ using Zn2EuxTi1-xO4 and Zn2-xEuxTiO4 systems where (X = 1%, 2% and 3%). The powders were calcined at 800°C and 1000°C for 4 hours with a heating rate of 5°C/min. The characterization was made by means of Thermal Analysis (TG/DSC), X-ray diffraction, scanning electron microscopy (SEM), Photocatalytic Activity Assay and Photoluminescence measurements (PL). The powders showed a variation in network parameters, such variation is probably a consequence of vacancies formation within the host network, driven by the entrance of the ion Eu3+ that has greater ionic radius than Ti4+. We obtained better results in the degradation tests in Zn2-xEuxTiO4 sample with 3%, that caused by defects in the crystal lattice due to doping and the withdrawal of zinc favoring the photocatalytic activity of titanium.. The photoluminescence spectra showed no characteristic peaks of Eu3+ due to the overlapping of the matrix, but increased significantly in intensity with increasing doping. The results show the potential of the polymeric precursor methods for obtaining Zn2TiO4 doped with Eu3+.