Preparation and characterization of the spinel oxide ZnCo2O4 obtained by sol-gel method

The zinc-cobalt-oxide spinel was obtained by the thermal decomposition of Zn-Co gel prepared by sol-gel method using oxalic acid as a chelating agent. The formation of spinel compound ZnCo2O4 has been confirmed by thermogravimetry (TGA) and X-ray powder diffraction (XRD) and Infra-red spectra (IR). It was shown that well-crystallized spinel structure is formed after calcination at 350 degrees C (low-temperature spinel). The particle size of 15 similar to 20 nm has been measured by transmission electron microscope (TEM). Non-isothermal kinetic parameters (E-a, f(alpha) and A) for the decomposition process of the oxalate precursor were determined using differential scanning calorimetry (DSC) under air atmosphere. The sol-gel method provides a practicable and effective route for the synthesis the spinel compound ZnCo2O4 at low temperature. (C) 2007 Elsevier B.V. All rights reserved.