Electrochimica Acta, Vol.256, 241-251, 2017
Ternary Ni-Fe-V sulfides bundles on nickel foam as free-standing hydrogen evolution electrodes in alkaline medium
Designing multiple transition metal sulfides with unique nanostructure may hold promising in highly efficient water electrolysis. Herein, ternary Ni-Fe-V sulfides nanobundles supported on nickel foam (NiFeVS/NF) with one-dimensional structure have been fabricated as efficient electrocatalysts for hydrogen evolution reaction (HER) in alkaline solution. Firstly, a facile electrodeposition realizes homogeneous dispersion of Fe on NF (Fe/NF). Secondly, hydrothermal sulfurization with introduction of V source can obtain ternary NiFeVS/NF. SEM and TEM show that one-dimensional NiFeVS nanobundles are observed to vertically cover on NF, providing abundant active sites with rapid charge transfer. The ternary NiFeVS/NF has superior activity with overpotential to 161 mV at 10 mA cm (2) than binary NiVS/NF, NiFeS/NF and single Ni3S2/NF. The possible synergistic effect of ternary Ni-Fe-V sulfides may lead to enhanced intrinsic activity confirmed by electrochemical active surface area (ECSA) and electrochemical impedance spectroscopy (EIS) data. Further, ternary NiFeVS/NF has robust stability in 10 h water electrolysis with unchanged bundle-like structure. Therefore, the synergistic effect derived from multiple transition metals and unique nanostructure may be the key for excellent electrocatalytic properties. (C) 2017 Elsevier Ltd. All rights reserved.
Keywords:ternary Ni-Fe-V;nanobundles;electrodeposition-hydrothermal process;alkaline hydrogen evolution