Key Words:Nickel compounds;Cobalt compounds - Electrocatalysis - Hydrogen - Shells (structures) - Sulfur compounds
Abstract:In this work, nickel cobalt bimetallic sulfide with typical multi-shell hollow sphere structure behaved superior electrocatalytic activity towards hydrogen evolution reaction (HER), which have been prepared through a easy method included solvothermal step, calcination step and in-situ sulfurization step. The composition and structure of the obtained nickel cobalt bimetallic sulfide are controlled through adjusting the sulfurization temperature and dosage of sulfur source. The as-prepared Ni–Co-S multi-shell hollow microspheres (abbreviated as Ni-Co-S) behaves superb HER properties in alkaline medium and Ni-Co-S-340(60) performs the most superior property, in which reflected the lowest overpotential (129 mV vs. RHE) at the current density of 10 mA cm<sup>−2</sup> and the smallest Tafel slope (96.1 mV dec<sup>−1</sup>) among all the synthesized samples. The superior electrocatalytic performance of the obtained Ni-Co-S-340(60) for HER is owing to the unique multi-shell hollow structure derived from the intrinsic porous character of Ni-Co-BTC MOF precursor in one hand. And in the other hand, introducing highly active NiCo<inf>2</inf>S<inf>4</inf> into NiS<inf>2</inf> would enhance its elctrocatalytic activity because of the strong interfacial effect between NiS<inf>2</inf> and NiCo<inf>2</inf>S<inf>4</inf>.<br/> © 2019 Elsevier Ltd
Volume:177
Issue:
Translation or Not:no
