Hierarchical Porous NiS@NiO Nanoarrays in Situ Grown on Nickel Foam as Superior Electrocatalyst for Water Splitting

This is the authors' abstract. We don't add key points for this paper.

The development of economic and efficient bifunctional water-sptting catalysts in case of the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is of considerable practical significance. Herein, a hierarchical porous NiS@NiO nanoarray with a large surface area was prepared in situ on nickel (Ni) foam as a water-splitting catalyst via a simple hydrothermal method. The core–shell NiS@NiO/NF hybrid exhibits an excellent bifunctional performance with low overpotentials of 150 and 319 mV to achieve an HER current density of 10 mA cm −2 and a large OER current density of 100 mA cm −2 , respectively, in the 1.0 M KOH solution because of its high specific surface area and the interface between the two phases. Furthermore, NiS@NiO/NF exhibits a cell voltage of 1.54 V for overall water splitting and extremely high stability for more than 50 h at 10 mA cm −2 . This study will help to design and develop high-performance hybrid nanomaterials via interfacial engineering for obtaining clean energy conversion technologies.