Synthesis of Peroxo-Modified Anatase Sol from Peroxo Titanic Acid Solution

Abstract

A peroxo titanic acid (PTA) solution has been prepared by mixing titanic acid wet gel and hydrogen peroxide solution. The PTA solution was a neutral, transparent, stable liquid. The PTA crystallized to form an anatase phase after calcination at a temperature above 250. When the PTA solution was autoclaved at a temperature above 100 for 6h, it changed to a sol containing anatase crystals less than 20nm in diameter. Aggregation occurred after autoclaving at a temperature above 120. When the PTA solution was heated to 100, it was translucent and stable in spite of containing ultrafine anatase crystals (9nm in diameter). It was deduced that the surfaces of anatase crystals are modified by the peroxo groups.

A new peroxo-route for the synthesis of Mg–Zr mixed oxides catalysts: Application in the gas phase acetone self-condensation

“…The second stage of decomposition in the range of 673-773 K is accompanied by an exothermic effect on the DSC curve; ascribed to the oxidation of the organic part of the complex. Furthermore, a maximum at 503 K is observed which could be attributed to the rupture of the O-O bridges and transition of the singlet oxygen to O 2-state, in agreement with the results obtained by Ichinose et al [39], in their studies about peroxotitanates. A third broad exothermic peak is also observed in the range of 928-1028 K, attributed to the polymorphic transitions in zirconia and magnesia systems (Supplementary Information).…”

Preparation and Characterization of Hydrophilic TiO2Film

“…Recently, a method to make the neutral sol using H 2 O 2 has been reported. 10,11 In this study, the neutral (pH=7) sol was synthesized by the addition of excess H 2 O 2 to the white precipitates obtained from TiCl 4 precursor. The reactions that occurred in this process could be expressed as follows.…”

Titania-based functional nanocomposite materials fabricated by liquid processes

“…29) Generally, heating gels in wet conditions results in crystallization of TiO 2 at lower temperature than that required to crystallize TiO 2 in a dry atmosphere. 19),26),30),31) Some nearroom-temperature crystallization methods for titania-based gels have been reported, including a chemical equilibrium reaction of aqueous ammonium hexafluorotitanatesolution, 32) and direct syntheses using peroxo-modified anatase sols 33) and aqueous titanium sulfate solution. 34) We have also reported several lowtemperature crystallizations of solgel-derived TiO 2 -based coatings with the assistance of water.…”