Electronic\nStructure Engineering of NiCoP Sites via\nN, Ru Dual Doping for Bifunctional Water Electrolysis

Exploiting highly effective electrocatalysts is a challenge\nfor\nboosting the overall efficiency of water splitting. Herein, we present\na nitrogen and ruthenium dual-doping strategy to tailor the electronic\nstructures of NiCoP(N, Ru–NiCoP), creating high-performance\nbifunctional electrodes for the hydrogen evolution reaction (HER)\nand oxygen evolution reaction (OER). The dual-doping approach is favorable\nfor electronic interactions within the NiCoP and CoP, yielding a near-zero\nGibbs free energy for H adsorption. Consequently, the optimized N,\nRu–NiCoP electrodes exhibit exceptional bifunctional activities,\nwith overpotentials of 53 and 405 mV at 100 mA cm<sup>–2</sup> for the HER and OER, respectively. Notably, their performance surpasses\nthat of commercial Pt/C and RuO<sub>2</sub> catalysts at large current\ndensities, demonstrating their potential for industrial water splitting\napplications. Moreover, the overall water-splitting device achieves\na current density of 10 mA cm<sup>–2</sup> with a driving voltage\nof only 1.54 V. This work provides an effective heteroatom doping\nstrategy to develop low-cost and highly active electrocatalysts.