Surface modulated Fe doping of β‐Ni(OH)₂ nanosheets for highly promoted oxygen evolution electrocatalysis

Abstract Active yet low‐cost electrocatalysts for water oxidation are crucial for the development of hydrogen energy economy. The Fe doping into Ni(OH)₂ dramatically enhances catalytic activity toward oxygen evolution reaction (OER) but fabricating Ni(OH)₂ of high Fe loading is still challenging. Herein, we report a one‐pot strategy to prepare disordered β‐Ni(OH)₂ nanosheets with a high Fe doping level (9.9 at%, D‐Fe‐Ni(OH)₂). By engaging 1,4‐phenylenediphosphonic acid (BDPA), Fe_xBDPA_y precursors are in situ generated in a growth solution containing Fe³⁺ ions, which decrease the reaction kinetics of Ni²⁺ and Fe³⁺ ions at the surface of Ni foam. This prevents the deconstructive hydrolysis by Fe³⁺ ions and enables a high Fe‐doping in D‐Fe‐Ni(OH)₂. The as‐prepared D‐Fe‐Ni(OH)₂ affords 10 mA cm⁻² at an ultralow OER overpotential of 194 mV in alkaline media. This work offers a promising strategy of engaging organic ligands to achieve high‐doping levels for the construction of efficient electrocatalysts. image