Study of influential factors in synthesis and characterization of cobalt oxide nanoparticles

This study has investigated the different factors in obtaining cobalt oxide nanoparticles. The factors that have been studied are the effect of pH, synthesis temperature, capping agent, annealing temperature, and different usage of cobalt salts. Cobalt oxide nanoparticles were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, UV, Fourier transform infrared spectroscopy, and X-ray diffraction. In order to find the effects of various factors, the optimum pH was achieved in the first experiment by the precipitation method; after finding out that in experiments with pH 8 to 9, the particles are homogeneous in shape and regular. The other experiments were repeated with the same pH but changing the factors. In the second experiment, the effect of synthesis temperature at 40°C, 60°C, 80°C, and 100°C was investigated. To find out the effect of capping agent, two experiments were done, one using the oleic acid and the other using 2-(dodecyloxy) acetic acid. In the case of investigating the annealing temperature, the black cobalt oxides were annealed at 400°C, 500°C, and 600°C. The last one was done using two different cobalt salts, cobalt nitrate and cobalt sulfate. Finally, cobalt oxide nanoparticles were characterized.