Electrocatalytic Oxidation Removal of Phenol from Aqueous Solution with Metal Oxides Doped Carbon Aerogel

Metal oxides (manganese oxide, MnO, manganese dioxide, MnO2, copper oxide, CuO, zinc oxide, ZnO and nickel oxide, NiO) doped carbon aerogel (CA) were prepared and used as catalysts in heterogeneous oxidation of phenol from aqueous solution in a three-dimensional (3D) electrode reactor. Textural characterization of metal oxides doped CA showed that the metal oxide nanoparticles are dispersed separately throughout the carbon matrix. The experimental results showed that phenol was degraded mainly by hydroxyl (•OH) radicals. The presence of metal oxides accelerated •OH radical generation. The •OH radical quantity depends on the type of metal oxide. The n-type semiconductor was more active than p-type semiconductor for •OH radical generation. Furthermore, acceleration effect of •OH radical generation catalyzed by metal oxides doped CA was investigated and demonstrated.