Transition metal and phosphorus co-doping induced lattice strain in mesoporous Rh-based nanospheres for pH-universal hydrogen evolution electrocatalysis

Abstract Rhodium (Rh) -based nanomaterials are promising alternatives to platinum (Pt) for the hydrogen evolution reaction (HER). However, the engineering and synthesis of Rh-based electrocatalysts to achieve Platinum-like HER performance under a comprehensive pH range still remains a challenge. In this work, we report an effective tactics to promote the HER performance of Rh mesoporous nanoparticles (Rh MNs) by co-doping of transition metal (e.g., Ni, Co, Fe) and phosphorus (P) elements. Such a metal-nonmetal co-doping could effectively regulate the electronic structure, increase the active sites, and induce lattice strain, which jointly contributes to a superior HER performance. With these merits, the optimized RhNiP mesoporous nanoparticles (RhNiP MNs) exhibited superior HER activity in a comprehensive pH scope, requiring overpotentials of only 15 mV, 36 mV and 44 mV in 0.5 M H2SO4, 1 M KOH and 1 M phosphate buffer solution (PBS), respectively, at the cathodic current density for 10 mA cm−2.