Bifunctional Heterostructure Assembly of NiFe LDH Nanosheets on NiCoP Nanowires for Highly Efficient and Stable Overall Water Splitting

TLDR

Hierarchical heterostructures of NiFe LDH on NiCoP nanowires are being investigated for electrocatalytic applications due to their engineered interfaces and synergistic effects. The study aims to develop a bifunctional NiFe LDH@NiCoP nanowire heterostructure as a cost‑efficient electrocatalyst for overall water splitting. The authors fabricated 3D NiFe LDH@NiCoP nanowire heterostructures on nickel foam via interface engineering to achieve synergistic catalytic activity. The NiFe LDH@NiCoP/NF electrodes deliver HER and OER overpotentials of 120 mV and 220 mV at 10 mA cm⁻², enable overall water splitting at 1.57 V, and maintain excellent stability for 100 h of continuous operation.

Abstract

Abstract 3D hierarchical heterostructure NiFe LDH@NiCoP/NF electrodes are prepared successfully on nickel foam with special interface engineering and synergistic effects. This research finds that the as‐prepared NiFe LDH@NiCoP/NF electrodes have a more sophisticated inner structure and intensive interface than a simple physical mixture. The NiFe LDH@NiCoP/NF electrodes require an overpotential as low as 120 and 220 mV to deliver 10 mA cm −2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1 m KOH, respectively. Tafel and electrochemical impedance spectroscopy further reveal a favorable kinetic during electrolysis. Specifically, the NiFe LDH@NiCoP/NF electrodes are simultaneously used as cathode and anode for overall water splitting, which requires a cell voltage of 1.57 V at 10 mA cm −2 . Furthermore, the synergistic effect of the heterostructure improves the structural stability and promotes the generation of active phases during HER and OER, resulting in excellent stability over 100 h of continuous operation. Moreover, the strategy and interface engineering of the introduced heterostructure can also be used to prepare other bifunctional and cost‐efficient electrocatalysts for various applications.