In pursuit of improved efficiency of electrochemical water splitting, a comprehensive understanding of the intricate mechanisms and methodologies to enhance the four-electron process of OER is paramount. Presently, two mechanisms holds way in the realm of science: the adsorbate evolution mechanism (AEM) and the lattice oxygen oxidation mechanism (LOM). Recent scientific investigations have highlighted that electrocatalytic materials featuring oxygen vacancies tend to adhere to the LOM mechanism, exhibiting heightened OER activity, and by tuning the oxidation states of the multivalent active sites followed the AEM OER mechanism. By attaining a comprehensive grasp of the mechanisms governing the OER, we hold the potential to engineer electrocatalysts that are not only economically viable but also capable of supplanting the current reliance on precious metal oxides like ruthenium and iridium. The zinc ferrite (ZnFe₂O₄) thin films on indium tin oxide and quartz substrates using RF-sputtering were deposited at ambient temperature with different argon/oxygen gas ratios, specifically 1:0 (Z-Ar), 1:1 (Z-Ar:O), and 0:1 (Z-O). The oxygen evolution reaction (OER) performances of the thin films are investigated to understand the effect of oxygen vacancies on electrochemical activity and observed that the Z-Ar film, with oxygen vacancies, exhibits a decrease in overpotential by ~12.5% at 10 mA-cm-2 , 8-fold increase in current density at 520 mV overpotential deduced from linear sweep voltammetry (LSV), and a 71.9% increase in donor density inferred from the Mott-Schottky plot, as compared to the Z-O film. The findings suggest that the Z-Ar film follows a “lattice oxygen participation mechanism” (LOM) for the OER instead of an “adsorbate evolution mechanism ” (AEM) observed in the Z-O film. Electronic state engineering of a high-valent active site for enhanced oxygen evolution reaction (OER), which was achieved through a novel electrochemical pre-cathodic treatment method (EPCTM). This method involves applying a cathodic potential to the drop-casted working electrode of hydrothermally synthesized Mn substituted nickel ferrite (N1-xMnxFe2O4; where x = 0.0, 0.2, and 0.4) electrocatalysts. X-ray photoelectron spectroscopy analysis revealed an increase in the ratios of Ni³⁺/Ni²⁺ and Mn³⁺/Mn²⁺ in Ni1-xMnxFe₂O₄ after electrochemical pre-cathodic treatment method (EPCTM) followed by OER, leading to an enhancement in electrochemical OER current density at 600 mV overpotential by 3.65 times for x = 0.0, 5.56 times for x = 0.20, and 4.72 times for x = 0.40