Oxygen-deficient Fe-CoMoO₄/NF: A high-performance electrocatalytic material for overcoming the catalytic bottleneck in water splitting and urea oxidation

Developing efficient and durable multifunctional electrocatalysts represents a promising way to address the challenges of resource crisis and environmental contamination. However, the delayed kinetics of the anodic oxygen evolution reaction (OER), which involves a sophisticated four-charge transfer route, is regarded as a major bottleneck for the commercialization of electrolyzed water. Herein, iron was successfully incorporated into cobalt molybdate grown on nickel foam substrate (Fe-CoMoO₄/NF) by a convenient hydrothermal-calcination strategy. Compared with numerous traditional molybdate, it exhibited superior trifunctional electrocatalytic reactivity and stability for hydrogen evolution reaction (HER), OER, and urea oxidation reaction (UOR) by reason of the regulation of electronic configuration and the inducement of abundant oxygen defects via Fe doping. Density functional theory (DFT) calculations indicated that Fe doping lowers the work function and shifts the d-band center of CoMoO₄, therefore optimizing the adsorption energy of hydrogen and oxygen intermediates. This study brings a profound insights for the structural design and the enhancement of properties of non-precious metal based multifunctional electrocatalysts.