Characterization of hydrous titania from titanous chloride—II. Infrared studies

Infrared studies were carried out on a number of titania gels prepared from titanous chloride under various conditions of pH and oxidizing agents. Oxygen oxidized gels display, below 1200 cm −1 , two bands at 1080 cm −1 and 970 cm −1 which are related to the formation of hydroxo complexes of titanium. Heat treatment at 110°C and ageing in water led to successive small shifts of these bands towards higher energies. In the case of hydrogen peroxide oxidized samples, prepared at a low pH, two significant bands appear at 1045 cm −1 and 1389 cm −1 and are attributed to O − 2 and HO 2 free radicals, respectively. The same kind of gels prepared under neutral or alkaline conditions are shown to incorporate hydroxo complexes of titanium; however, ageing in water leads to the reappearance in these gels of the 1045 cm −1 band attributable to O − 2 free radicals. All gels exhibit two sharp bands at around 1400 cm −1 and 1630 cm −1 , characteristic of NH + 4 ions and molecular water, respectively.