Electrosorptive removal of copper ions from wastewater by using ordered mesoporous carbon electrodes

Electrosorption performance of copper ions from wastewater on ordered mesorporous carbon (OMC) electrode was investigated. The OMC was synthesized by replication using SBA-15 as template and sucrose as carbon source. The OMC were characterized with nitrogen physisorption, transmission electron microscopy and X-ray photoelectron spectroscopy analysis. The OMC electrodes were prepared by blending the synthesized OMC, conductive carbon black, and PVDF binder. A conventional recycling batch system was adopted in the adsorption/electrosorption investigation in both open circuit and electrochemical polarization experiments. At pH = 4, the saturated adsorption capacity of copper ion (Cu2+) on the OMC electrode was determined 9.53 mg/g at open circuit. The equilibrium electrosorption capacity at polarization of 0.9 V was 56.62 mg/g, which is about 5 times higher than that at open circuit. The electrosorption isotherm data can be well described by Langmuir equation. The kinetics analysis indicated that the electrosorption of Cu2+ on OMC electrodes followed pseudo-second-order kinetics model. A commercial highly microporous activated fiber cloths were selected as electro-adsorbent of Cu2+ for comparison.

► Electrosorption of Cu2+ on OMC electrode and ACF cloths was investigated.
► Electrosorption capacity of OMC at 0.9 V is 5 times higher than at open circuit.
► Initial electrosorption rate of Cu2+ on OMC electrode is faster than on ACF cloths.