Three‐Dimensional Sea Urchin‐Like Structured Self‐Supported Electrode Ru‐NiCoP as Efficient Bifunctional Electrocatalyst for Overall Water Splitting

ABSTRACT Efficient and cost‐effective electrocatalysts play a crucial role in the alkaline water splitting for H 2 production. In this study, we successfully synthesized a three‐dimensional (3D) sea urchin‐like Ru‐NiCoP self‐supporting electrocatalyst deposited on nickel foam which exhibits good electrocatalytic performance in water splitting. In 1 M KOH aqueous solution, only the low overpotentials of 79.5 mV and 225.2 mV are required to achieve the current density of 10 mA·cm −2 for the hydrogen evolution reaction and oxygen evolution reaction, respectively. For overall water splitting (OWS), a cell voltage of only 1.52 V is needed to generate the current density of 10 mA·cm −2 . Furthermore, the electrode shows long‐term stability for OWS, maintaining its performance for 80 h even at a high current density of 50 mA·cm −2 . The good electrocatalytic performance can be ascribed to the unique 3D sea urchin‐like nanostructure and the synergistic effect of multiple transition metal phosphides in regulating the surface electronic structure. This work provides ideas for developing new precious‐metal‐saving self‐supporting electrodes.