Anchoring Polydopamine on ZnCo₂ O₄ Nanowire To Facilitate Urea Water Electrolysis

To overcome the sluggishness of the oxygen evolution reaction (OER), the urea oxidation reaction was developed. In the case of OER application studies ZnCo₂ O₄ is an excellent electrocatalyst, towards the UOR has been performed with surface-grown polydopamine (PDA) with surface-grown polydopamine (PDA). ZnCo₂ O₄ @PDA is produced over the surface of nickel foam by a hydrothermal method followed by self-polymerization of dopamine hydrochloride. Dopamine hydrochloride was varied in solution to study the optimal growth of PDA necessary to enhance the electrochemical activity. Prepared ZnCo₂ O₄ @PDA was characterized by X-ray diffraction, electronic structural, and morphology/microstructure studies. With successful confirmation, the developed electrode material was applied to UOR and ZnCo₂ O₄ @PDA-1.5, delivering an excellent low overpotential of 80 mV at 20 mA cm^-2 in the electrolyte mixture of 1 M potassium hydroxide+0.33 M urea. To support the excellent UOR activity, other electrochemical properties such as the Tafel slope, electrochemical surface active sites, and electrochemical impedance spectroscopy were also studied. Furthermore, a schematic illustration explaining the UOR mechanism is shown to allow a clear understanding of the obtained electrochemical activity. Finally, urea water electrolysis was carried out in a two-electrode symmetrical cell and compared with water electrolysis. This clearly showed the potential of the developed material for efficient electrochemical hydrogen production.