Silver decorated NiFe2O4 /CuWO4 Electrocatalyst for Oxygen Evolution Reactions

Abstract

In this work, Ag nanoparticles decorated NiFe2O4 /CuWO4 heterostructure were synthesized using the step-wise co-precipitation method. The influence of varying Ag loading on the NiFe2O4 /CuWO4 heterostructure and its electrochemical OER performance was extensively studied in 1 M KOH electrolyte. The obtained LSV profile was analyzed to determine the overpotential, Tafel slope, and onset potential. The heterostructure with an optimal Ag loading of 5 wt% required the least overpotential (1.60 V vs. RHE) for generating a current density of 10 mA cm-2 with a lower Tafel slope of 44.5 mV dec-1, indicating its faster OER kinetics. Furthermore, the composite remained stable over a prolonged period of 24 hours. The enhanced OER performance of the as prepared catalyst can be attributed to the presence of multiple metallic elements in the Ag-loaded NiFe2O4 /CuWO4 composite, which created a diverse array of oxygen-vacant sites with varying reactivity, enhancing the charge-transfer kinetics; and thus contributing to the overall efficiency of OER. Therefore, optimizing the Ag concentration and engineering a microstructure represents an encouraging strategy for developing cost-effective catalysts for next-generation energy-conversion applications.