Synthesis, structural and optical properties of pure ZnO and Co doped ZnO nanoparticles prepared by the co-precipitation method

Pure ZnO and Cobalt (Co) doped ZnO nanoparticles (NPs) were synthesized by the co-precipitation method. The synthesized nanoparticles retained the wurtzite hexagonal structure, which was confirmed by X-ray diffraction studies. From FESEM studies, ZnO and Co doped ZnO NPs showed Spherical and nanorod mixed phase and Spherical like morphology, respectively. The amount of dopant (Co2?) incorporated into ZnO sample was determined by EDAX. The FT-IR spectra confirmed the Zn–O stretching bands at 438 and 427 cm-1 for ZnO and Co doped ZnO NPs. From the UV–VIS spectroscopic measurements, the excitonic pecks were found around 376 and 370 nm for the respective samples. The photoluminescence measurements revealed that the broad emission was composed of seven different bands due to zinc vacancies, oxygen vacancies and surface defects. The dynamic light scattering (DLS) and Zeta potential measurements were used to find out the size and surface charges.