Nanoarchitectonics of High Surface Area Mesoporous Carbon Using a Non‐Pluronic Rubber‐Based Block Copolymer Template for Energy Storage: Synergistic Effects of Ozone Treatment and Potassium Hydroxide Activation

ABSTRACT Non‐Pluronic rubber‐based block copolymers (BCPs), such as polystyrene‐ b ‐polybutadiene‐ b ‐polystyrene (SBS), offer several advantages for mesoporous carbon (MC) fabrication, including larger micelle sizes, higher carbon content, improved thermal stability, and a higher glass transition temperature compared to traditional Pluronic BCPs. However, the lack of hydrophilic groups in SBS hinders its direct use in MC synthesis due to poor affinity with carbon precursors. In this study, we demonstrate that ozone treatment of SBS introduces polar carboxylate groups, enhancing the interaction between the BCP template and carbon precursors during MC fabrication via solvent evaporation‐induced self‐assembly. Scanning electron microscopy (SEM) reveals that MC materials derived from the ozone‐treated template (CSBS‐O 3 and ACSBS‐O 3 ) exhibit smaller particle sizes compared to those from the untreated template (CSBS and ACSBS). Subsequent KOH activation of CSBS‐O 3 yields ACSBS‐O 3 , which features a high surface area of 859 m 2 g −1 and a pore volume of 0.268 cm 3 g −1 . Electrochemical impedance spectroscopy shows that ACSBS‐O 3 exhibits a steeper slope (2.52) in the Nyquist plot at intermediate frequencies than ACSBS (1.02), indicating more efficient charge storage via electric double‐layer formation. The Bode plot displays a higher phase angle at low frequencies for ACSBS‐O 3 , reflecting improved capacitive behavior. Cyclic voltammetry results show that ACSBS‐O 3 achieves a specific capacitance of 300 ± 7.1 F g −1 at 5 mV s −1 , which is attributed to its enhanced surface area and optimized pore structure. Overall, this study demonstrates that ozone treatment of a non‐Pluronic SBS BCP template, combined with chemical activation, is an effective strategy for fabricating high‐performance MC materials with promising applications in energy storage devices.