Organophosphorus Layer-Modified CoFe-LDH/Co(OH)₂ Electrocatalyst: Green Synthesis and Mechanistic Insights into...

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 IrO₂. 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.