Confining FeNi x /Ni 2 P Mott–Schottky Cluster on 1D/2D Dimorphic Phosphorus/Nitrogen Codoped Carbon for High-Performance Oxygen Evolution Reaction

Rational interface engineering of Mott–Schottky junctions has emerged as a powerful approach to precisely regulating electronic configurations and boosting electrocatalytic oxygen evolution reaction (OER) kinetics. Herein, we demonstrate novel FeNi x /Ni 2 P Mott–Schottky clusters confined within P, N-codoped carbon nanosheets (PNCNSs)/carbon nanotubes (CNTs) (FeNi x /Ni 2 P-CNTs@PNCNSs), fabricated through a controlled two-stage pyrolysis–phosphidation protocol using bimetallic FeNi precursors. The synergistic coupling between metallic FeNi x and semiconducting Ni 2 P induces interfacial charge redistribution, while the dimorphic carbon matrix simultaneously establishes 3D conductive networks and prevents nanoparticle aggregation. As a result, the optimized catalyst achieves benchmark OER activity in 1 M KOH with a low overpotential of 217 mV (10 mA cm –2 ), a small Tafel slope of 37 mV dec –1, and excellent durability. Advanced characterization reveals the remarkable electrocatalytic behaviors derived from (i) more exposed electrochemical active sites, (ii) accelerated charge transfer via built-in metal–semiconductor interfaces and high-conductive carbons, and (iii) optimized binding energy from the Mott–Schottky junction. This method provides a promising strategy for integrating transition metal alloys and corresponding composites to assemble Mott–Schottky structures toward high-activity, low-cost oxygen evolution electrolysis.