Semi-ionic C-F optimizes metal-support interaction of Rh/F, N-codoped porous carbon for efficient all-pH hydrogen production

Designing efficient and robust Rh-based electrocatalysts with strong metal-support interaction for hydrogen evolution reaction (HER) across various pH conditions is of great significance and challenge. Herein, a hydrogel sealing-pyrolyzing-etching strategy is engineered to anchor ultrafine Rh nanoparticles (Rh NPs) on N-doped porous carbon (Rh/NPC), further introducing strong electronegativity F-dopants to strengthen the metal-support interaction for obtaining high electroactivity Rh NPs/ F, N-codoped porous carbon composite (Rh/FNPC) toward HER. The optimal 8Rh/FNPC renders ultralow overpotentials in 1 M KOH (η 10 = 12 mV), 0.5 M H 2 SO 4 (η 10 = 42 mV), and 1 M phosphate buffer solution (η 10 = 64 mV). Density functional theory (DFT) simulations unveil that the F dopants can optimize the adsorption free energies of reaction intermediates and accelerate the rate-determining steps on the Rh active site, thereby achieving high intrinsic activity and exceptional electroactivity of Rh/FNPC. This work affords new perspectives and avenues for constructing advanced catalysts in various catalytic applications. This study engineers an innovative hydrogel sealing-pyrolyzing-etching strategy to construct the semi-ionic C-F modified N-doped porous carbon/ultrafine Rh nanoparticles composite (Rh/FNPC) for HER. The Rh/FNPC affords appealing electrocatalytic performances across a wide pH range. The semi-ionic C-F in Rh/FNPC accelerates HER activity and kinetics of the Rh active sites by favoring the charge transfer of metal-support, lowering the energy barriers of rate-determining steps and reducing the adsorption free energies of reaction intermediates. • Constructing ultrafine Rh nanoparticles/F, N co-doped porous carbon electrocatalyst. • Rh/FNPC exhibits exceptional electrocatalytic activity in pH-universal HER. • Semi-ion C-F in Rh/FNPC optimizes the metal-support interaction. • F-doping promotes HER activity and kinetics of the Rh active sites in Rh/FNPC.