I Single‐Atom Doped P‐Rich CoPn Nanocluster@CoP with Enhanced HER

Abstract Constructing I single‐atom (I SA ) doped CoP electrocatalyst for HER is extremely challenging and has not been reported to date. Herein, an I SA doping‐phosphatization strategy is proposed to prepare a novel I single‐atom doped P‐rich CoP n nanocluster@CoP electrocatalyst (I SA ‐CoP n /CoP) with enhanced HER performance first. I SA ‐CoP n /CoP shows a low overpotential of only 44 and 81 mV in 0.5 m H 2 SO 4 solution, to drive a current density of 10 and 100 mA cm −2 . I SA and P‐rich CoP n nanocluster show unique synergies, which can optimize the H adsorption energy and accelerate the kinetics of HER in the CoP system. The intermediate I─H bond vibration peak is directly observed through in situ Raman testing, demonstrating that I SA doping helps accelerate the HER process. Additionally, the ΔG H of I SA ‐CoP n /CoP is only 0.05 eV by density functional theory (DFT) calculation, which is conducive to H 2 evolution.