Journal of Materials Science, Vol.48, No.4, 1533-1542, 2013
Effects of reaction parameters on solution combustion synthesis of lepidocrocite-like K0.80Ti1.733Li0.267O4: phase formation and morphology evolution
A lepidocrocite-like potassium lithium titanate K0.80Ti1.733Li0.267O4 (KLTO) with layered structure was synthesized by an auto-igniting solution combustion method using glycine and metal (Ti, K and Li) nitrate as reactants. The crystalline structure and morphology of the as-prepared product were examined using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. Effects of reaction parameters such as ignition temperature and oxidizers to fuel ratio on the phase formation and morphology evolution are investigated in this paper. A pure phase of KTLO was obtained at a low temperature (650 degrees C) within several minutes. Excessive glycine added into the aqueous precursor solution facilitated the synthesis of a pure and well-crystallized product. As-prepared particles exhibited plate-like shape with a length of 5-20 mu m and a thickness of about 2 mu m. No residual organic compound existed in the product. After the as-prepared product was post solution combustion heat-treated (1100 degrees C for 2 h), the particles became uniform in size with smooth surface and well-defined crystalline structure. The product exhibited excellent ion-exchange, intercalation, and exfoliation properties. The exfoliated titania nanosheets are characterized by high two-dimensional anisotropy with a thickness of about 20 nm and a lateral size ranging from sub-micrometers to several tens of micrometers.