Synergistic Electronic Modulation by Iron Doping and Phosphorization in Cobalt-Molybdenum Hydroxide Nanosheets on Iron Foam for Boosting Alkaline Oxygen Evolution

Designing highly efficient and durable non-precious electrocatalysts for the oxygen evolution reaction (OER) in alkaline media remains a critical challenge for sustainable hydrogen production via water electrolysis. Herein, we report a hierarchical electrocatalyst composed of iron-doped cobalt molybdenum phosphide nanoarrays in-situ grown on iron foam (Fe-CoMoP@IF) via a facile hydrothermal synthesis followed by subsequent phosphorization and iron doping. The introduced iron dopants effectively modulate the electronic structure of CoMoP, and the interconnected nanosheet architecture anchored on conductive IF ensures a large electroactive surface area and robust structural integrity. The synergistic integration of multiple compositional and structural advantages facilitates mass/charge transfer and boosts the active sites. Therefore, the optimized Fe-CoMoP@IF requires an overpotential of 238 mV at 10 mA cm−2 in alkaline electrolyte, which is superior to the control samples and other reported transition metal phosphides-based electrocatalysts. The low values of Tafel slope and charge transfer resistance prove the rapid reaction kinetics during the OER process. This work provides a feasible strategy for constructing highly active electrocatalysts through heteroatom doping and nanoengineering and offers insights for the rational design of advanced electrocatalysts for hydrogen production.