Tailoring Ni‐Fe‐B Electronic Effects in Layered Double Hydroxides for Enhanced Oxygen Evolution Activity

Abstract NiFe layered double hydroxides (LDHs) are state‐of‐the‐art catalysts for the oxygen evolution reaction (OER) in alkaline media, yet they still face significant overpotentials. Here, quantitative boron (B) doping is introduced in NiFe LDHs (ranging from 0% to 20.3%) to effectively tailor the Ni‐Fe‐B electronic interactions for enhanced OER performance. The co‐hydrolysis synthesis approach synchronizes the hydrolysis rates of Ni and Fe precursors with the formation rate of B─O─M (M: Ni, Fe) bonds, ensuring precise B doping into the NiFe LDHs. It is demonstrated that B, as an electron‐deficient element, acts as an “electron sink” at doping levels from 0% to 13.5%, facilitating the transition of Ni 2+ to the active Ni 3+δ , thereby accelerating OER kinetics. However, excessive B doping (13.5–20.3%) effectively generates oxygen vacancies in the LDHs, which increases electron density at Ni 2+ sites and hinders their transition to Ni 3+δ , thereby reducing OER activity. Optimal OER performance is achieved at a B doping level of 13.5%, with an overpotential of only 208 mV to reach a current density of 500 mA cm −2 , placing it among the most effective OER catalysts to date. This Ni‐Fe‐B electronic engineering opens new avenues for developing highly efficient anode catalysts for water‐splitting hydrogen production.