Self-supported hierarchical CoFe-LDH/NiCo2O4/NF core-shell nanowire arrays as an effective electrocatalyst for oxygen evolution reaction

Abstract

Design and synthesis of three-dimension (3D) nanowire arrays (NWAs) electrocatalyst with a core-shell structure have been considered as an efficient way to enhance the performances for the oxygen evolution reaction (OER). In this work, novel hierarchical CoFe-LDH/NiCo2O4/Ni foam (CoFe-LDH/NCO/NF) core-shell nanowire arrays have been fabricated via a facile two-step strategy. The as-obtained nanocomposites were characterized by multiple methods, and their electrocatalytic properties for OER have also been evaluated. The unique structural and component features for the as-prepared 3D nanocomposites facilitate the enhancement of the OER performances. CoFe-LDH/NCO/NF nanocomposites display an excellent OER electrocatalytic activity with a low overpotential of 273 mV at 20 mA cm−2, as well as an outstanding long-term electrochemical stability with a 90% current preservation during a 32 h test. The remarkable electrocatalytic performances of the CoFe-LDH/NCO/NF electrode ascribe to the strong synergistic effect between the NiCo2O4 (NCO) nanowires core and the CoFe-LDH nanosheets shell at the interface. Our work provides a novel sight on the rational design of 3D core/shell nanoarrays electrode materials for OER.