Tungsten doping-Induced electronic structure modulation in NiFe-based metal-organic frameworks for enhanced oxygen evolution reaction

Abstract

NiFe-based metal-organic frameworks (MOFs) are promising low-cost and easily prepared non-precious catalysts for the oxygen evolution reaction (OER). However, effectively modulating the electronic structures in these electrocatalysts remains a critical challenge. In this study, we successfully incorporated tungsten into FeNi-MOF to synthesize W-doped FeNi2.4-MIL-53 and achieved electronic structure modulation. The results show that the optimized FeNi2.4W0.05-MIL-53 exhibits a lowe overpotential of 235 mV at a current density of 10 mA cm−2, low Tafel slope of 43.3 mV dec−1, and high cyclability over 1000 cycles. Density functional theory (DFT) calculations demonstrate that the conversion from O* to OOH* is the rate-determining step on the active sites of FeNi2.4W0.05-MIL-53. The incorporation of tungsten induces an upshift of the d-band center of the active site, effectively modulating the adsorption energy of oxygen intermediates, thereby enhancing the catalytic activity.