Codoped Cr and W rutile nanosized powders obtained by pyrolysis of triethanolamine complexes

Polycrystalline, rutile phase, nanosized mixed transition metal oxide, with compositions Cr2xWxTi1−3xO2 (x = 0.05, 0.1, 0.15), have been prepared through pyrolysis of aqueous precursor solutions containing stoichiometric amounts of ammonium dichromate, dimethylammonium tungstate, titanium oxalate and optimum amounts of TEA. The rutile phased oxide solid solutions obtained on calcination of the precursors at 800 °C have been characterized by XRD, TG-DTA, BET surface area measurement, UV–visible spectroscopy and TEM. Substitution of Cr(III) for Ti(IV) ions in the rutile lattice causes colouring effect in the solid solutions while the W(VI) ions are incorporated for charge compensation. The nanosized powders of the solid solutions exhibit buff colour and their average particle sizes and specific surface areas are found to range between 30–60 nm and 56–68 m2/g, respectively. Various TiO2-based mixed oxides of variant colours can be prepared through the developed chemical process.