Insights of enhanced oxygen evolution reaction of nanostructured cobalt ferrite surface

The present study includes the process to tune the morphology of CoFe2O4 nanostructures via hydrothermal route and their effect on oxygen evolution reaction (OER). The control of size and morphology has been done via the pH and varying hydrothermal reaction time. Transmission electron microscopy reveals the formation of ~ 20 nm CoFe2O4 nanocube after 24 h reaction time. As-prepared samples deposited over graphite substrate and used as a working electrode for catalysis. CoFe2O4 nanocubes offer better O2 evolution activity in terms of current density (48 mAcm−2), lower onset potential (η1 = 260 mV) and overpotential (η10 = 430 mV) compared to nanoparticles. The low Tafel slope value (44 mVdec−1) of CoFe2O4 nanocube confirms the faster kinetics compared to CoFe2O4 nanoparticles. The effect of electrochemical active surface area, roughness factor (Rf), wettability properties and surface-active species on the OER performance has been studied.