Organophosphorus Layer‐Modified CoFe‐LDH/Co(OH) 2 Electrocatalyst: Green Synthesis and Mechanistic Insights into Enhanced Oxygen Evolution Activity

Abstract A green phosphating method is developed to synthesize phytate‐modified CoFe‐LDH/Co(OH) 2 nanosheets for efficient oxygen evolution reaction (OER), eliminating toxic gas emissions. By optimizing the amount of phytic acid (PA), a uniform 120 nm phosphorus‐containing coating is formed while preserving the layered double hydroxide structure. The resulting PA 0.5 ‐CoFe‐LDH/Co(OH) 2 exhibits superior OER performance, with an overpotential of 260 mV at 10 mA cm −2 and a Tafel slope of 32.95 mV dec −1 , outperforming IrO 2 . Although the P‐layer slightly reduces the electrochemical surface area, it significantly enhances the intrinsic activity of single active sites. In situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the P‐layer facilitates charge transfer, improves intermediate adsorption/desorption, and protects active sites from over‐oxidation. Density functional theory calculations show that P‐doping lowers the energy barrier of the rate‐limiting step ( * O → * OOH) from 0.77 to 0.70 eV by optimizing intermediate adsorption. The catalyst retains 98.09% of its activity after 200 h at 100 mA cm −2 , demonstrating exceptional long‐term stability. This work offers valuable insights for designing eco‐friendly, high‐performance, phosphorus‐regulated OER electrocatalysts.