Utilization of Coinage Metals as an Efficient Dopant Protocol for Enhancing Asymmetric Supercapacitors and Oxygen Evolution Reactions

Doped polyaniline (PANI) was synthesized using low concentrations of Ag and Cu coinage metals in order to evaluate their impact on energy conversion and storage performances. During the preparation of PANI, a chemical oxidation polymerization process was followed by concurrent doping with Ag and Cu. The nanoparticles were found to have typical orientations when examined by scanning electron microscopy (SEM). X-ray diffraction (XRD) was used to examine the crystal structure of the synthesized doped PANI materials, which confirmed their crystalline nature. Ag-Cu-doped PANI samples demonstrated a more pronounced reduction in optical band gap as compared to other doped samples. Based on Fourier transform infrared spectroscopy (FTIR) analysis, it can be concluded that the synthesized materials possess large functional groups. Compared to other enhanced PANI materials in an alkaline electrolyte, Ag-Cu enriched PANI exhibited superior oxygen evolution reaction (OER) and supercapacitor performances. The presence of the oxygen evolution reaction activity (OER) in a 1 M KOH solution was observed at an overpotential of 340 mV at a current density of 10 mA/cm². Using Ag-Cu-doped PANI as the anode electrode material, asymmetric supercapacitors produced an energy density of 211.75 W h/kg at a current density of 4.5 A/g, demonstrating their superior performance. The obtained results described high cycle stability over 50,000 galvanic charge–discharge cycles at a current density of 4.5 A/g, and a 102% capacitance retention rate was described by the electrode material. Despite low concentrations of Ag and Cu dopants, the coinage metals can be effectively used as dopants for the fabrication of next-generation practical energy storage devices.