Electrocatalytic activity and
electrochemical hydrogen storage of
Ni-La alloy prepared by
electrodeposition from aqueous
electrolyte
electrochemical hydrogen storage of
Ni-La alloy prepared by
electrodeposition from aqueous
electrolyte
(1.Department of Chemistry, Zhejiang University,
Hangzhou 310027, China；
2.College of Environment and Chemical Engineering,
Shanghai University, Shanghai 200027, China；
3.Department of Applied Chemistry, Tianjin University,
Tianjin 300072, China)
Hangzhou 310027, China；
2.College of Environment and Chemical Engineering,
Shanghai University, Shanghai 200027, China；
3.Department of Applied Chemistry, Tianjin University,
Tianjin 300072, China)
Abstract: Ni-La alloy coating was prepared by electrodeposition. The effect of cathodic current density on the La content of the alloy coatings was discussed. It is found that the content of La in the alloy increases with increasing the cathodic current density. The microstructures and codeposition mechanism of Ni-La alloy coatings were investigated by means of X-ray diffraction (XRD) and cyclic voltammetry (CV). The results demonstrate that the Ni-La alloy is FCC and codeposited by the induced mechanism. The hydrogen evolution reaction (HER) on the electrodeposited Ni-La alloy electrodes in alkaline solution was evaluated by Tafel polarization curves. It is found that La-Ni alloy coating exhibits much higher exchange current density for HER than pure Ni electrode, and that the exchange current density increases with increasing the La content of alloys. The good electrocatalytic activity for HER of this Ni-La alloy is attributed to the synergism of the electronic structure of La and Ni. The electrodeposited La-Ni alloys have a certain electrochemical hydrogen storage capacity of 34～143mAh/g, which increases with increasing the La content of alloys.
Key words: Ni-La alloy; electrodeposition; hydrogen evolution reaction; hydrogen storage