Photocatalytic oxidation of methyl ethyl ketones over sol-gel mesoporous and meso-structured TiO2 films obtained by EISA method

摘要

This work reports the influence of the meso-structure of TiO2 films in the photocatalytic oxidation of methyl ethyl ketone. Five types of TiO2 films were prepared combining the sol-gel route with the Evaporation Induced Self-Assembly (EISA) method. Sols were prepared from titanium tetrachloride (TiCl4) using different types of pore generating agents. Films characterisation was performed by Fourier Transform Infrared Spectroscopy (FT1R), Grazing X-ray diffraction (GXRD), X-ray diffraction of small angle and Transmission Electron Microscopy (FE-SEM). Environmental Ellipsometric Porosimetry (EEP) studies were performed to obtain the adsorption/desorption isotherms and calculate porous size distribution, pore volume and specific surface area (S_s) of the films. Kinetic of MEK photocatalytic oxidation data were modelled by Langmuir-Hinshelwood equation and the adsorption and kinetics constants (k and K) were calculated. Better results of MEK degradation were obtained for the Brij58 films deposited at relative humidity (RH) of 20% and 50%. The results are correlated with the porosity properties of the films.