Preparation of Ni/GO 0.2 -PAC 0.8 particle electrode and its degradation performance of Cu-EDTA complex

Abstract

Cu-EDTA has strong stability in water and is hard to remove by conventional chemical precipitation methods. The particle electrode that was applied in the electrocatalytic degradation of Cu-EDTA was prepared by impregnation roasting method, using the powdered activated carbon (PAC) and graphene oxide (GO) as the carrier, and nickel as the catalyst. XRD and SEM-EDS were performed to characterize the composition and morphology of the electrode surface. The efficiency and mechanism of Cu-EDTA decomplexation and copper recovery were investigated. The results showed that the optimal conditions of the preparation of particle electrode were: the calcination temperature of 600 ℃, the calcination time of 4 h, and the mass ratio of PAC to GO of 8: 2. The nickel on the particle electrode existed mainly as Ni0, and a small amount of NiO. The decomplexation efficiencies of Cu-EDTA and total complexing copper (TCCu) were 99.6% and 99.4%, respectively. The recovery efficiency of total copper (TCu) was 93.7%. The decomplexation and copper recovery processes were in accordance with pseudo-first order reaction kinetical model. The results of free radical quenching and cyclic voltammetry scanning experiments showed that the decomplexation of Cu-EDTA was completed by electro-reduction. Cu2+ in Cu-EDTA was first reduced to Cu+, then reduced to Cu0 and deposited on the particle electrodes.