Synthesis of nanocrystalline Li4Ti5O12 by a novel aqueous combustion technique

Lithium titanate (Li4Ti5O12) powder has been synthesized by a novel aqueous combustion process using a common amino acid alanine, as fuel. Thermogravimetric analysis of the gel indicates sharp single step combustion at similar to 200 degrees C where nearly 80% weight loss occurs. X-ray analysis shows that the as-synthesized powder contains mostly spinel Li4Ti5O12 phase along with anatase TiO2. About 90% phase purity is obtained when calcined at 800 degrees C in air. Observation Under a Field Emission Scanning Electron Microscope reveals spherical shaped particles with uniform morphology. The particle size as estimated from the micrograph is in the range 40-80 nm. Fourier transformed infrared spectroscopy shows the characteristics bands of Li4Ti5O12 at 652 and 462cm(-1) even in the as-synthesized powder. A wide optical band gap of 1.80eV has been determined from UV-vis spectroscopy. (C) 2007 Elsevier B.V. All rights reserved.