Catalytic ozonation of phenol in aqueous solution by Co3O4 nanoparticles

Abstract

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.