关键词: 玻碳材料, 电沉积, 纳米晶体镍, 催化性能

Abstract: Nanocrystalline nickel exhibits electrocatalytic activity for methanol. In this work, nanocrystalline nickel coating has been obtained by using the double pulse method on glassy carbon materials surface. The influence of pulse conditions on the grain size of nanocrystalline nicke was studied. The concentrations and compositions of the plating bath were  300 g·L^-1 NiSO₄·6H₂O，45 g·L^-1 NiCl₂·6H₂O，40 g·L^-1 H₃BO₃，5 g·L^-1 C₇H₅NO₃S，and 0.05 g·L^-1 C₁₂H₂₅NaO₄S. The optimal pulse process parameters including the average pulse current density of 100 mA·cm^-2, pulse duty ratio of 30%, pulse frequency of 1000 Hz, pH of 1.5, and treatment temperature of 55 ℃ were determined. The grain size, surface morphology, structure and electrochemical properties of the prepared nanocrystalline nickel were investigated by XRD, TEM, cyclic voltammetry and electrochemical impedance spectroscop. Accordingly, the dense, smooth, and continuous uniform electrodeposition layer with the typical face-centered cubic structure was developed. The average size of the nanocrystalline nickel was about 18 nm. Cyclic voltammetric and electrochemical impedance spectroscopic results showed that the nanocrystalline nickel electrodeposited on the glassy carbon surface had good electrocatalytic activity for methanol in an alkaline environment.

Key words: glassy carbon material, electrodeposition, nanocrystalline nickel, catalytic performance