Synergetic Engineering of Metal–Organic Framework Derived FeNi Layered Double Hydroxides for Efficient and Stable Overall Water Splitting

Abstract

Exploring efficient, low-cost, overall water splitting (OWS) electrocatalysts is crucial to achieving large-scale hydrogen (H 2 ) production. Here, we describe the synthesis of Co, V codoped FeNi-based layered double hydroxides (Co,V-FeNi-LDHs) 3D hierarchical structures as bifunctional electrocatalysts on nickel foam (NF) using Zeolitic imidazolate framework-67 (ZIF) as a template. Herein, ZIF not only acts as a framework for morphology engineering but also functions as a Co atom source, along with creating more active sites. A dual-doping strategy with Co and V leads to lattice distortion and stronger electronic interactions in the electrocatalyst, thereby increasing its active surface area and intrinsic activity, with excellent electrocatalytic performance. The resulting Co,V-FeNi-LDH electrocatalyst exhibited excellent bifunctional activities. The overpotentials of the oxygen evolution reaction at 50 mA cm −2 and the hydrogen evolution reaction at 10 mA cm −2 are 244 and 180 mV, respectively. Moreover, a cell voltage of 1.62 V was achieved at a current density of 10 mA cm −2 with excellent stability of 60 h. This study emphasizes the significance of enhancing the electrocatalytic performance of LDH through a synergistic approach involving dual cation doping and morphology engineering.