Enhanced Electrocatalytic Activity of Sm2O3-doped Ni-Co Coating Electrode for Hydrogen Evolution Reaction
In this work, HER was investigated on Ni-Co alloy electrode and Ni-Co-Sm2O3 composite electrode in 0.50 M Na2SO4 + 0.10 M H2SO4 solution. It was indicated that Sm2O3 particles promoted the formation of an amorphous structure of Ni-Co alloy coating, which was benefit for HER. The surface of Ni-Co-Sm2O3 composites was more coarse and grainy compared with that of Ni-Co alloy layer (Fig. 1). Steady-state polarization curves (Fig. 2) showed that the hydrogen evolution potential of Ni-Co-Sm2O3 composite electrode positively moved by about 240 mV at 8.0 mA cm-2 compared with that of Ni-Co alloy electrode, indicating that the embedded Sm2O3 particles enhanced the electrocatalytic activity of Ni-Co coating for HER. Furthermore, Ni-Co-Sm2O3 composite electrode has considerably lower charge transfer resistance and higher exchange current density.
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