Interfacial engineering of core/satellite-structured RuP/RuP2 heterojunctions for enhancing pH-universal hydrogen evolution reaction

Developing renewable hydrogen technologies requires high-efficiency pH-universal hydrogen evolution reaction (HER) electrocatalysts. Ruthenium phosphides (RuP_x) have great potentials to replace the commercial Pt-based materials, whereas the optimization of their electronic structure for favorable reaction intermediate adsorption remains a significant challenge. Herein, we report an innovative phosphorization-controlled strategy for the in-situ immobilization of core/satellite-structured RuP/RuP₂ heteronanoparticles onto N, P co-doped porous carbon nanosheets (abbreviated as RuP/RuP₂@N/P-CNSs hereafter). Density functional theory (DFT) calculations further reveal that the electron shuttling at the RuP/RuP₂ interface leads to a reduced energy barrier for H₂O dissociation by electron-deficient Ru atoms in the RuP and the optimized H∗ adsorption of electron-gaining Ru atoms in the RuP₂. Impressively, the as-synthesized RuP/RuP₂@N/P-CNSs exhibits low overpotentials of 8, 29, and 66 mV to achieve 10 mA cm⁻² in alkaline, acid and neutral media electrolyte, respectively. This research presents a viable approach to synthesize high-efficiency transition metal phosphide-based electrocatalysts and offers a deeper comprehension of interface effects for HER catalysis.