Characterization of Sol-gel Prepared Silica Supported NiO-CuO Composites

Abstract

Silica (SiO2) supported nickel oxide-copper oxide (NiO-CuO) composites were synthesized through alkoxide route of sol-gel process using tetraethyl ortthosilicate (TEOS), nickel nitrate hexahydrate and copper nitrate trihydrate as precursors. A series of different compositions were prepared varying NiO:CuO molar ratios keeping all other process parameters constant. The gels thus obtained were calcined at a moderate temperature i.e. 500and#186;C for one hour. The crystal structure and thermal stability of metal oxide particles embedded in silica matrix were studied using X-ray diffraction technique (XRD) and differential scanning calorimetry (DSC-TGA) respectively. The purity of the composites was checked by Infrared spectroscopy (IR) whereas the composite formation was confirmed by scanning electron microscopy. The results revealed that crystals of NiO and CuO nanoparticles aggregated to form spheres of variable sizes were successfully embedded in the amorphous silica matrix composed of silica particles agglomerated to form clusters.