I Single-Atom Doped P-Rich CoP_n Nanocluster@CoP with Enhanced HER

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 H₂SO₄ 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 H₂ evolution.