Synthesis and structural analysis of ZnO-NiO mixed oxide nanocomposite prepared by homogeneous precipitation

ZnO-NiO mixed oxide nanocomposite as well as ZnO and NiO nanoparticles were prepared by a simple homogeneous precipitation method from the metal nitrates and calcined at 200 °C and 500 °C. XRD results indicate that the NiO crystallites in the mixture after calcination at 500 °C for 2 h are larger than the ZnO crystallites. The dislocation density decreased for all samples with an increase in crystallinity. The volume fractions of the ZnO and NiO phases in the mixture determined by the direct comparison approach amounts to 35% for ZnO phase and 65% for the NiO phase. The elemental composition obtained from energy dispersive X-ray (EDX) shows a relatively higher concentration of Ni than Zn with an atomic ratio of Ni/Zn = 0.69.