Pyrolysis study of sol-gel derived TiO2 powders: Part IV. TiO2-anatase prepared by hydrolysingtitanium(IV) isopropoxide without chelating agents

An amorphous TiO₂ gel was obtained by hydrolysing titanium(IV) isopropoxide with a stoichiometric amount of water using SnCl₂ as catalyst. In these operative conditions, a TiO₂ gel matrix containing a lower fraction of organic residual was obtained with respect to samples prepared by previously modifying the titanium alkoxide precursor with chelating ligands. Dried gel powders were characterized by N₂ adsorption analyses, FT-IR and XRD measurements. Thermogravimetric (TG) and differential thermal analysis (DTA) coupled with mass spectrometric (MS) and gas chromatographic (GC) measurements were performed in order to identify the organic products released from TiO₂ gel pyrolysis. The Tg-MS semiquantitative analysis of the main evolved species allowed to describe both the chemical composition of the initial TiO₂ gel and the chemical rearrangements occurring in the matrix during heating up to its crystallisation to anatase form at 420°C.This revised version was published online in November 2005 with corrections to the Cover Date.