Effect of the Activating Agent on the Pore Structure of Chimney-Soot-Derived Carbon Materials Used as Supercapacitors

This study investigated physically and chemically activated chimney soot to evaluate the influence of the activation process on the textural properties and porous structure of materials intended for use in supercapacitors. The materials were characterized by Raman spectroscopy to analyze molecular structure and composition, as well as BET analysis to determine porosity and structural properties based on N2 adsorption-desorption isotherms. Their electrochemical characteristics were evaluated using a two-electrode configuration with cyclic voltammetry, galvanostatic charge–discharge measurements, and long-term cycling tests of up to 10,000 cycles within a voltage window of 0.05–1.0 V in a 1 M KOH electrolyte. Soot-based symmetric supercapacitors activated with KOH at а ratio of 3:1 exhibit a specific capacitance of 74–78 F g−1 at 0.2 A g−1 and achieve an energy density of 2.3 Wh kg−1 at a power density of 32 W kg−1. The results demonstrate that, by carefully controlling the type and quantity of the activating agent, chemical activation is an effective method for increasing the specific surface area and improving the electrochemical characteristics of the resulting materials. Chemical activation significantly expands the microporous framework, optimizing ion transport at the electrode–electrolyte interface. The results demonstrate the successful valorization of chimney soot as functional carbon electrodes for next-generation energy storage applications.