One‐Step Synthesized Ni ₆ Fe ₄ ‐BD Nanorods With Dual Functional Ligands Combined With Double‐Coordinated Metals for Enhancing Overall Water Splitting

ABSTRACT A viable strategy for harnessing hydrogen energy that can be sustainably supplied, conveniently stored, and transported lies in the advancement of electrocatalytic materials tailored for water electrolysis. These catalysts must exhibit exceptional activity, long‐term operational stability, and economic viability. Metal–organic frameworks (MOFs) have recently emerged as a class of electrocatalytic materials with tailored superiority. This is because they possess an ultrahigh specific surface area along with numerous potential active sites. In this paper, we designed and synthesized a special bimetallic and double‐ligand MOF nanomaterial. Within a 1‐M KOH solution, the synergistic interaction of two metal ions and the electron‐transfer influence of dual ligands boost the electron‐transfer efficiency of the oxygen‐generating electrochemical process (formally designated as OER) and overall water electrolysis. For the prepared Ni 6 Fe 4 ‐BD@NF nanomaterial, at 15 mA cm −2 , the electrode achieves a remarkably low OER overpotential of 270 mV, accompanied by an ultralow Tafel slope of 22.77 mV dec −1 . At 100 mA cm −2 , the OER overpotential measured exhibits a value of 390 mV. The electrocatalytic performance of the Ni 6 Fe 4 ‐BD@NF nanocomposite significantly outperforms its single‐metal counterparts with distinct ligand coordination environments. Specifically, at 15 mA cm −2 , the overpotential required for OER is 320 mV for Ni‐BD@NF (double‐ligand system), 340 mV for Ni‐B@NF, and 360 mV for Ni‐D@NF (single‐ligand system). When integrated into a full water electrolysis cell, the system operates at a voltage of 1.509 V for 100 h to attain a current density of 20 mA cm −2 . Experimental findings demonstrate that the incorporation of metal ions, the design of double‐ligand MOFs, and nanoization of MOF materials are straightforward and effective approaches to enhance the electrocatalytic properties of MOFs.