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

Exploring efficient, low-cost, overall water splitting (OWS) electrocatalysts is crucial to achieving large-scale hydrogen (H2) 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.