Synergistic electronic and morphological modulation on ternary Co 1− x V x P nanoneedle arrays for hydrogen evolution reaction with large current density

It is a great challenge to prepare non-noble metal electrocatalysts toward hydrogen evolution reaction (HER) with large current density. Synergistic electronic and morphological structures of the catalyst have been considered as an effective method to improve the catalytic performance, due to the enhanced intrinsic activity and enlarged accessible active sites. Herein, we present novel ternary Co 1− x V x P nano-needle arrays with modulated electronic and morphological structures as an electrocatalyst for highly efficient HER in alkaline solution. The NF@Co 1− x V x P catalyst shows a remarkable catalytic ability with low overpotentials of 46 and 226 mV at current densities of 10 and 400 mA cm −2 , respectively, as well as a small Tafel slope and superior stability. Combining the experimental and computational study, the excellent catalytic performance was attributed to the improved physical and chemical properties (conductivity and surface activity), large active surface area, and fast reaction kinetics. Furthermore, the assembled Co-V based electrolyzer (NF@Co 1− x V x -HNNs(+)||NF@Co 1− x V x P(−)) delivers small full-cell voltages of 1.58, 1.75, and 1.92 V at 10, 100, and 300 mA cm −2 , respectively. Our findings provide a systematic understanding on the V-incorporation strategy to promote highly efficient ternary electrocatalysts via synergistic control of morphology and electronic structures.