Sol-gel and low-temperature solvothermal synthesis of photoactive nano-titanium dioxide

Photoactive nano-titanium dioxide, as anatase phase, was obtained by the sol-gel method coupled with the solvothermal technique at short crystallization time (2 h) and low temperature (200 degrees C), using tetraisopropyl orthotitanate as Ti-precursor and 2-propanol as solvent. Precursor ratios were evaluated to determine their influence in the synthesis. Methyl orange was used as model molecule for the photocatalytic degradation. Highest anatase crystallinity was obtained when the water content is close to the stoichiometrically needed to hydrolyze a molecule of TIOT and these materials also showed the highest methyl orange photodegradation. (C) 2012 Elsevier B.V. All rights reserved.