A nickel-loaded activated carbon (Ni/AC) composite particle electrode was prepared by electroless deposition with palladium-free pretreatment to improve the electrocatalytic performance of a composite particle electrode in a three-dimensional electrode cell. The preparation conditions of the Ni/AC particle electrode were optimized using the decolorization ratio of methyl orange dye solution as an index. The composite particle electrodes were characterized by scanning electron microscopy, X-ray diffraction, and energy dispersive spectrometry analyses. The electrocatalytic performances of the Ni/AC particle electrode were examined by a series of parameters, including particle electrode dose, sodium sulfate concentration, cell voltage, and electrolysis time. The results were compared with those of conventional activated carbon (AC) particle electrode. These results indicated the feasibility of preparing a Ni/AC composite particle electrode by electroless plating with non-palladium pretreatment. The optimal conditions for preparing the Ni/AC electrode were 40 g L-1 NiSO4·6H2O, 27 g L-1 NaH2PO2·H2O, 50 °C plating temperature, and 20 min plating time. The electrocatalytic performance of Ni/AC electrode was superior to that of AC electrode under the same electrolysis conditions. The rate constant of the Ni/AC electrode electrochemical oxidation of methyl orange was 1.5 times larger than that of AC electrode.
composite particle electrode; electroless plating; palladium free; preparation; electrocatalytic performance
