Catalytic Ozonation of Phenol in Aqueous Solution by Co3O4Nanoparticles

The degradation efficiencies of phenol in aqueous solution were studied by semi-continuous experiments in the processes of ozone alone, ozone/bulky Co₃O₄ and ozone/ Co₃O₄ nanoparticles. Catalyst samples (bulky Co₃O₄ and Co₃O₄ nanoparticles) were characterized by X-ray diffraction and transmission electron microscopy. The Brunauer-Emmett-Teller surface area, pHpzc and the density of surface hydroxyl groups of the two catalyst samples were also measured. The catalytic activity of Co₃O₄ nanoparticles was investigated for the removal of phenol in aqueous solutions under different reaction temperatures. Tert-butyl alcohol had little effect on the catalytic ozonation processes. Based on these results, the possible catalytic ozonation mechanism of phenol by Co₃O₄ nanoparticles was proposed as a reaction process between ozone molecules and pollutants.