The effect of Ce doped in Ti/SnO₂-Sb₂O₃/SnO₂-Sb₂O₃-CeO₂ electrode and its electro-catalytic performance in caprolactam wastewater

Ti/SnO₂-Sb₂O₃/SnO₂-Sb₂O₃-CeO₂ anodes were prepared by brush coating with high temperature oxidation. The anodes were characterized by X-ray diffractometer (XRD), scanning electron microscope and cyclic voltammetry. The surface of the electrode shows more compact and exist shallower mud cracks than the others by coating with 1% Ce to the surface of Ti/SnO₂-Sb₂O₃ electrode. The XRD patterns show that as-prepared electrodes are SnO₂ and TiO₂. The electrode with 1% Ce dopant shows the highest efficiency in the electrolysis of caprolactam wastewater. The oxygen evolution potential is about 1.75 V, the removal rate of chemical oxygen demand is 50%, and the biochemical oxygen demand is 353 mg/L for 5 h at a current of 0.12 A.