INFLUÊNCIA DA PRESSÃO SOBRE A SUPERFÍCIE DO TiO2E SEU EFEITO NA FOTODEGRADAÇÃO CATALÍTICA DO HERBICIDA 2,4-D

Abstract

The purpose of this study was to obtain, characterize and evaluate the photocatalytic activity of the surface modified titanium dioxide in relation to the unmodified titanium dioxide. Titanium dioxide (TiO2) anatase (commercial) was introduced into an oven made, with the function of modifying the external surface of the oxide by the effect of pressure, temperature and time. The modified titanium (TM) oxides and unmodified (TN) were characterized by the techniques of X-ray diffraction (XRD)and refinement by the Rietveld method, transmission electron microscopy (TEM) and determination of specific surface area. In heterogeneous photodegradation tests, degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was accompanied by UV/vis, high performance liquid chromatography efficiency (HPLC) and determination of total organic carbon (TOC). The influence of pressure on the surface of titanium dioxide resulted in a change in the external surface of titanium dioxide, surface irregularities increases, without changes in unit cell parameters and increases the surface area. The photocatalytic activity of the modified titanium dioxide (TM) was higher to the unmodified titanium dioxide (TN).The modified titanium dioxide had a higher percentage of degradation of the herbicide 2,4-dichlorophenoxyacetic acid and a higher mineralization making it more efficient.