Physicochemical, catalytic, and antimicrobial activities of porous cobalt oxide nanoparticles (kinetics study of H2O2 decomposition using fluorometric and gasometric methods)

Co3O4 nanomaterials were prepared by different methods. The samples were nominated as Co3O4 (Pr), Co3O4 (Co), and Co3O4 (Hy) due to preparation by precipitation, combustion, and a hydrothermal method, respectively. These nanomaterials were characterized by studying their structural, morphological, and surface properties. The catalytic activity was evaluated by following H2O2 decomposition through fluorometric and gasometric methods. The obtained results showed that the catalytic efficiency of the catalysts was affected by their preparation methods. The order of catalytic activities of the investigated samples using fluorometric method is compatible with that obtained by gasometric method. Co3O4 (Hy) exhibited much higher catalytic activity due to the high surface area, small particle size, different oxidation states, different shapes, and the high production of hydroxyl radical. The antimicrobial activity is studied against standard bacterial and fungal strains, and the studies showed that the hydrothermal method enhanced antimicrobial activity more than other preparation methods.