Three-dimensional electrochemical degradation of p-aminophenol with efficient honeycomb block AC@Ti-Cu-Ni-Zn-Sb-Mn particle electrodes

Abstract

Emerging contaminants such as pharmaceuticals has been one of the most challenging environmental problems. In this work, we developed a one-step facile sol–gel method of loading TiO2, CuO, NiO, ZnO, Sb2O3 and MnO onto honeycomb block activated carbon (AC@Ti-Cu-Ni-Zn-Sb-Mn), further applying as particle electrodes in a three-dimensional electrochemical system for the efficient degradation of p-aminophenol (PAP). Factors associated with the preparation of AC@Ti-Cu-Ni-Zn-Sb-Mn particle electrodes were investigated. The AC@Ti-Cu-Ni-Zn-Sb-Mn particle electrodes were analyzed by scanning electron microscope (SEM), energy dispersive spectrum analysis (EDX), X-Ray Diffraction analysis (XRD), Brunner-Emmet-Teller (BET) and X-ray Photoelectron spectroscopy (XPS). The effects of conductivity, pH value, aeration intensity, current density, conductivity and initial concentration on PAP degradation were also studied. Importantly, the PAP degradation results show that the activity of the particle electrodes supported by block honeycomb activated carbon is much better than that of the particle electrodes supported by granular activated carbon. The removal efficiency of PAP achieved approximately 99.87% under the optimized condition. The pathway study suggested that the quinoneimine is the major intermediate during the three-dimensional electrochemical degradation and OH radicals play important roles in the reaction. Overall, its facile fabrication and efficient electrochemical degradation performance indicate that the proposed honeycomb block particle electrodes have potential for practical applications of refractory organic pollutants.