Morphological characterization of sphere-like structured ZnO-NiO nanocomposites with annealing temperatures

Abstract Three-dimensional (3D) sphere-like structured zinc oxide (ZnO) – nickel oxide (NiO) nanocomposites were prepared via a simple one-pot solution process. Their morphological properties were investigated as a function of the annealing temperature in the range 300–700 °C. Metal hydroxides (Zn(OH)2 and Ni(OH)2) were completely decomposed to metal oxides (ZnO and NiO), respectively, after annealing at 500 °C. Field emission scanning electron microscopy (FESEM) images revealed that the sphere-like structures maintained their shapes during the annealing treatment. The interwoven nanowalls that constituted sphere-like structures were themselves a sheet-like assembly of nanoparticles, which increased in size with increase in annealing temperature. After annealing at 700 °C, a network of interconnected nanoparticles could be observed.