Facile synthesis of self-doped carbon derived from waste tires as an efficient supercapacitor electrode material

Waste materials have become a promising source for producing carbonaceous materials, that can be utilized in energy storage system as well as in wide range of applications. The growing accumulation of waste tires presents significant environmental challenges, but also offers an opportunity to convert them into valuable carbon-based materials for energy storage applications. In the present study, a facile and scalable approach has been demonstrated to synthesizing self-doped, heteroatom-enriched carbon from waste tires via catalytic pyrolysis followed by hydrochloric acid (HCl) leaching. The resulting chemically treated carbon (CTC), derived from pyrolytic carbon char (CC), exhibits a porous microstructure and is doped with multiple heteroatoms, as confirmed through comprehensive characterization techniques, including X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and N2 adsorption desorption Brunauer-Emmett-Teller (BET) isotherm. The electrochemical performance of both CC and CTC was evaluated in a symmetric two-electrode configuration using 1 M tetraethylammonium tetrafluoroborate (TEABF4) in acetonitrile (ACN) organic electrolyte. The CTC exhibited significantly enhanced capacitive performance compared to CC, achieving a specific capacitance of 346.67 Fg- 1 at 1 A g- 1, alongside excellent energy density (39 Wh kg- 1) and power density (450 W kg- 1). Notably, the CTC retained 90% of its initial capacitance after 10,000 charge-discharge cycles at a current density of 10 A g- 1, demonstrating excellent cycling stability. This work presents a facile, and sustainable approach for repurposing waste tires into high-performance electrode materials for supercapacitors.