NiSe@Ni<sub>1−<i>x</i></sub>Fe<sub><i>x</i></sub>Se<sub>2</sub> Core–Shell Nanostructures as a Bifunctional Water Splitting Electrocatalyst in Alkaline Media
Dmitrii Rakov, Chunyu Sun, Ziang Lu, Siwei Li, Ping Xu
Abstract
Herein a facile synthesis methodology is reported that results in a unique 3D NiSe@Ni 1− x Fe x Se 2 core–shell nanostructure on nickel foam substrate, where Ni 1− x Fe x Se 2 nanosheets are fabricated on NiSe nanowires through an iron‐doping‐induced phase transformation process under solvothermal conditions. This material demonstrates stable hydrogen and oxygen evolution activity in 1.0 m KOH with a small overpotential of 153 mV@ − 10 mA cm −2 and 236 mV@100 mA cm −2 , respectively. Furthermore, an efficient and stable water electrolyzer with NiSe@Ni 1− x Fe x Se 2 /nickel foam as both anode and cathode is fabricated, which requires a low overpotential of 1.60 V to deliver a current density of 10 mA cm −2 . Such ion‐doping‐induced phase transformation paves a new way for fabricating highly efficient electrocatalysts for energy storage and conversion.