Synthesis and characterization of nanosized zinc aluminate spinel by sol–gel technique

Abstract

Nanosized zinc aluminate spinel has been obtained by the thermal decomposition of Zn–Al gel prepared by sol–gel technique using oxalic acid as a chelating agent. Stirring an enthanol solution of zinc nitrate, aluminium nitrate and oxalic acid yields a gel precursor, followed by calcination of the resulting gel at different temperatures. Thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC) have been used to study the thermal behaviour of the precursor. Powder X-ray diffraction (XRD) show that the sample obtained by heating the precursor at 700 °C for 5 h is single-phase cubic material having the spinel-type structure, which can be confirmed by Infrared spectra (IR). The particle size of 15–20 nm has been measured by transmission electron microscopy (TEM). The specific surface area determined by BET surface area measurement was found to be 58 m 2 g −1.