Enhanced electrocatalytic OER performance of Ba/CS-CoFeO ternary heterostructure catalyst: Experimental and theoretical insights.

Herein, a ternary heterostructure catalyst Ba/CS-CoFeO (barium/chitosan-doped Cobalt ferrite) was developed by a straightforward co-precipitation technique to investigate oxygen evolution reaction (OER) activity. Varying quantities (2 and 4 wt %) of Ba and a fixed amount (3 wt %) of CS were doped to modify the surface area, porosity, crystallite size, and stability of CoFeO. Comprehensive characterizations revealed multiple phases, polycrystalline behavior, enhanced absorption, structural defects, and nanorods overlapping nanoparticles (NPs) like the morphology of Ba/CS-CoFeO. Furthermore, the experimental results revealed that 2 wt % of Ba/CS-CoFeO exhibited superior electrocatalytic activity with the highest kinetics and ECSA (electrochemically active surface area) for the OER process in 1 M KOH. To further elucidate the OER performance, density functional theory (DFT) calculations were conducted. The optimized CoFeO structure was confirmed to have a cubic Fd-3m symmetry, with a calculated bandgap energy (E) of 1.62 eV, closely matching experimental data. Adsorption energy calculations showed that Ba/CS doping significantly improved the binding strength of OH intermediates on the CoFeO (100) surface, highlighting the role of dopants in enhancing surface reactivity. These findings demonstrate the potential of Ba/CS doping to optimize the electronic, structural, and surface properties of CoFeO for efficient OER electrocatalysis, paving the way for novel electrochemical catalyst design.