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

Efficient and cost-effective electrocatalysts play a crucial role in the alkaline water splitting for H₂ 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.