Synergistic electrocatalysis for oxygen evolution reaction using novel polypyrrole integrated CoWO₄ in alkaline solution

Abstract

A novel synthesized composite of cobalt tungstate (CoWO₄) and polypyrrole (ppy) was effectively developed by hydrothermal method, followed by in situ polymerization. The first time reported CoWO₄/ppy composite was characterized by implementing numerous physicochemical methods like XRD, XPS, HR-TEM, and FT-IR. The further assessment of electrochemical performance was conducted through LSV, CV, EIS, and Tafel polarization measurements. The composite demonstrated significant catalytic activity for the alkaline water oxidation reaction (WOR), attaining an extremely low overpotential of 170 mV at a current density of 10 mA cm⁻² (η10) and a Tafel slope of 61 mV dec⁻¹. The values demonstrate a significant enhancement over the individual electrocatalytic performances of CoWO₄ and polypyrrole, highlighting the synergistic effect of the composite. The superior electrocatalytic activity of the composite material is further validated by its lowest charge transfer resistance (15 Ω) and standard energy of activation (18.57 kJ mol⁻¹), indicating enhanced electron transport and reduced energy barriers for the reaction. The research indicates that CoWO₄/ppy serves as a promising material for efficient electrocatalytic applications. © 2025 Elsevier B.V.