Surface modification of the La- Mg-Ni alloy with Ag related to the electrocatalytic properties

In order to prevent La-Mg-Ni hydrogen storage alloy from generating inert electrode in alkaline electrolyte and affect its electrocatalytic performance for BH4-, this study proposed surface modification of La-Mg-Ni hydrogen storage alloy with Ag. La-Mg-Ni@Ag composite hydrogen storage alloy catalysts with different Ag contents were synthesized by photo-deposition method, and the structure and electrocatalytic properties of the alloy samples were investigated in detail. Microstructural studies revealed that the La-Mg-Ni@Ag composite alloy formed a core-shell structure with the larger La-Mg-Ni alloy particles as the core and the fine Ag particles as the shell. Among the studied alloy samples, the surface morphology of La-Mg-Ni @Ag1.1 composite alloy was the best, and the fine Ag particles covered the La-Mg-Ni alloy particles most tightly and uniformly. Electrochemical studies revealed that the surface modification of La-Mg-Ni alloy by Ag resulted in a significant improvement in the charge transfer capacity of the surface of the alloy electrodes as well as in the electrocatalytic performance and stability towards BH4-. Among them, the La-Mg-Ni @Ag1.1 composite alloy showed the best electrocatalytic performance, which was attributed to its favorable microstructure.