Urchin-Like Nanorods of Binary NiCoS Supported on Nickel Foam for Electrocatalytic Overall Water Splitting

The pursuit of clean and sustainable energy has greatly motivated the development of efficient and robust electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, we report on the fabrication of the urchin-like NiCoS nanorod arrays supported on nickle foam (NF) by electrodeposition-hydrothermal reaction process. Notably, during the hydrothermal process, molybdate and P123 are used directly as indispensable structure-directing agents for the growth of urchin-like nanorods. Moreover, the obtained urchin-like NiCoS nanorod presents as a highly active oxygen evolution reaction anode with a current density of 100 mA cm(-2) at the overpotential of 360 mV. Combined with its excellent catalytic performance as hydrogen evolution reaction cathode with 50 mA cm-2 at an overpotential of 200 mV in 1 M KOH. XRD show that the mixed phases of CoS, Co9S8 and Ni3S2 coexisted in the NiCoS/NF. SEM images illustrate that the average diameter of urchin-like NiCoS nanorod is about 100 nm, demonstrating the successful fabrication of urchin-like NiCoS nanorod arrays. The enhanced electrocatalytic activity of NiCoS may drive from the synergistic effect of the mixed transition metal sulfides and the unique urchin-like nanostructure of NiCoS. (C) 2018 The Electrochemical Society.