Biomimetic Fe₇S₈/Carbon electrocatalyst from [FeFe]‐Hydrogenase for improving pH‐Universal electrocatalytic hydrogen production

Abstract

Abstract Efficient and cost‐effective electrocatalysts that can operate across a wide range of pH conditions are essential for green hydrogen production. Inspired by biological systems, Fe 7 S 8 nanoparticles incorporated on polydopamine matrix electrocatalyst were synthesized by co‐precipitation and annealing process. The resulting Fe 7 S 8 /C electrocatalyst possesses a three‐dimensional structure and exhibits enhanced electrocatalytic performance for hydrogen production across various pH conditions. Notably, the Fe 7 S 8 /C electrocatalyst demonstrates exceptional activity, achieving low overpotentials of 90.6, 45.9, and 107.4 mV in acidic, neutral, and alkaline environments, respectively. Electrochemical impedance spectroscopy reveals that Fe 7 S 8 /C exhibits the lowest charge transfer resistance under neutral conditions, indicating an improved proton‐coupled electron transfer process. Continuous‐wave electron paramagnetic resonance results confirm a change in the valence state of Fe from 3+ to 1+ during the hydrogen evolution reaction (HER). These findings closely resemble the behavior of natural [FeFe]‐hydrogenase, known for its superior hydrogen production in neutral conditions. The remarkable performance of our Fe 7 S 8 /C electrocatalyst opens up new possibilities for utilizing bioinspired materials as catalysts for the HER.