Preparation of nanodispersed titania using stabilized ammonium nitrate melts

Abstract

An expedite one-step approach using simple precursors has been proposed to obtain metallic oxide compounds and exemplified by preparation of highly dispersed TiO 2. The technique consists in heating to 400–500 °C of molten ammonium nitrate stabilized with an organic nitrogen-containing compound (urea, melamine, ammonium oxalate) and containing dissolved metal salt precursor (TiOCl 2). The crystallites of the resulting TiO 2 demonstrated variable size and shape as a function of stabilizer used. Their activity in photocatalytic oxidation of formic acid also depends on the nature of the stabilizer. The catalysts as-prepared showed high photocatalytic performance, superior to that of the Degussa P25 reference. Nitrogen containing stabilizers play a double role of increasing the process safety and modifying the properties of the solid products.