Influence of some sol-gel synthesis parameters of mesoporous tio2 on photocatalytic degradation of pollutants

Abstract

Titanium dioxide (TiO2) nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor by varying some parameters of the sol-gel synthesis, such as temperature (500 and 550 degrees C) and the duration of calcination (1.5, 2 and 2.5 h). X-ray powder diffraction (XRPD) results have shown that all synthesized nanopowders were dominantly in the anatase phase, with the presence of a small amount of rutile in samples calcined at 550 degrees C. According to the results obtained by the Williamson-Hall method, the anatase crystallite size was increased with the duration of the calcination (from 24 to 29 nm in samples calcined at lower temperature, and from 30 to 35 nm in samples calcined at higher temperature). The analysis of the shift and line-width of the most intensive anatase Eg Raman mode confirmed the XRPD results. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 5-8 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16), car-bofuran ray scattering.