Study on Electrodeposited Ni-S and Ni-P-S Alloy Cathodes for Hydrogen Evolution

On the basis of Ni-S alloy electrode made by electrodeposition method, Ni-P-S alloy electrode was obtained by adding sodium hypophosphite monohydrate into the bath.The tested electrochemical properties show that electrochemical activities of Ni-P-S alloy electrode and Ni-S alloy electrode are much higher than those of other electrodes,the increment of sodium hypophosphite monohydrate concentration would reduce the activity of Ni-P-S alloy electrode.Furthermore,the corresponding electrode kinetic parameters,such as Tafel slope b,the exchange current density ρ~0 and the overpotential η,were calculated,then the reason why Ni-P-S alloy electrode and Ni-S alloy electrode had different activity in different current density area was explained.The high electrochemical stability of Ni-P-S alloy electrode was determined by constant-current electrolysis.Finally,The micrographs of electrode surface were investigated by SEM.The mass contents of elements in coatings were measured by EDS,and the structure of alloy cathodes were analyzed by XRD.