Metal-organic framework derived NiFe2O4/FeNi3@C composite for efficient electrocatalytic oxygen evolution reaction

Abstract

Reducing the cost and improving the electrocatalytic activity are the key to developing high efficiency electrocatalysts for oxygen evolution reaction (OER). Here, bimetallic NiFe-based metal-organic framework (MOF) was prepared by solvothermal method, and then used as precursor to prepare NiFe-based MOF-derived materials by pyrolysis. The effects of different metal ratios and pyrolysis temperatures on the sample structure and OER electrocatalytic performance were investigated and compared. The experimental results showed that when the metal molar ratio was Fe: Ni = 1:5 and the pyrolysis temperature was 450°C, the sample (FeNi₅-MOF-450) exhibits a composite structure of NiFe₂O₄/FeNi₃/C and owns the superior electrocatalytic activity in OER. When the current density is 100 mA·cm⁻², the overpotential of the sample was 377 mV with Tafel slope of 56.2 mV·dec⁻¹, which indicates that FeNi₅-MOF-450 exhibits superior electrocatalytic performance than the commercial RuO₂. Moreover, the long-term stability of FeNi₅-MOF-450 further promotes its development in OER. This work demonstrated that the regulatory methods such as component optimization can effectively improve the OER catalytic performance of NiFe-based MOF-derived materials.