Ni-Co Doped M-type Strontium Hexaferrite as Electrode Material for Oxygen Evolution Reaction

Abstract

In the field of sustainable and renewable energy, developing highly active electrode materials for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) remains a significant challenge. Herein, we have used novel M-type hexaferrites, SrCo_xNi_xFe_12−2xO₁₉ materials, prepared using sol-gel auto-combustion (SGAC) route, for water splitting, in which Co and Ni elements were used as doping materials. Six different compositions of hexaferrites were prepared by varying the concentrations of Co and Ni elements. The fabricated electrode materials were then well characterized by various advanced analytical tools such as XPS, PXRD, BET, FTIR, FE-SEM, and HR-TEM to evaluate their chemical composition, oxidation state, crystallinity, porosity, functional groups and morphology. These prepared electrocatalysts were used as electrode materials for OER and HER application. The rich heterostructural interfaces and unique morphology effectively accelerate the transition of electrons and expose highly active sites for chemical reactions. Among the prepared electrocatalysts, the one with x = 1.0 (SrNi6) shows better OER activity in terms of potential and kinetic activity. ECSA and EIS studies were also conducted to support the electrochemical observations, and the results were found to be consistent with the OER and HER results. Therefore, the fabricated electrocatalysts are suitable for electrochemical applications.