CoFe₂O₄ surface modification with conducting polypyrrole: employed as a highly active electrocatalyst for oxygen evolution reaction

Electrochemical water splitting could be a potentially viable technique for obtaining the energy from renewable sources. The considerable overpotential demanded for sluggish oxygen evolution reaction (OER), however, prevents broad adoption of this approach. Herein, CoFe₂O₄/PPY hybrid is synthesized with a polypyrrole layered on the top of the CoFe₂O₄ via facile hydrothermal treatment. CoFe₂O₄/PPY is a highly efficient electrocatalyst, because it outperforms than pure CoFe₂O₄, PPY in terms of OER. CoFe₂O₄/PPY OER activities are comparable to those of commercial electrocatalysts. It's worth noting that the CoFe₂O₄/PPY hybrid is significantly more stable than the individuals, due to surface coated with PPY, responsible for good conduction of fast-moving electrons. The CoFe₂O₄/PPY coupling increases the OER by promoting electron exchange between the PPY layer and the CoFe₂O₄ reducing the over potential of (274 mV) and also lower the Tafel slope (47 mV/dec) with lower charge transfer resistance (3.15 Ω). According to the findings, on the top of CoFe₂O₄, a layer of PPY is applied for the surface modification using a conducting polymer can improve spinel oxides activity for future applications such as photoelectrocatalytic study, for stabilizing the material activity, etc.