π-Conjugated Triazine–Benzotrithiophene COF Networks Integrated with Carbon Nanotubes and Reduced Graphene Oxide in Cellulose Films for High-Performance Supercapacitors

This study presents the synthesis of a covalent organic framework (TPBT-COF) via the Schiff-base reaction and its integration with carbon nanotubes (CNTs) and reduced graphene oxide (rGO) through in situ polymerization, yielding TPBT@CNT and TPBT@rGO composites. To develop environmentally friendly electrode materials, the TPBT@CNT and TPBT@rGO composites were blended with regenerated cellulose (RC), forming TPBT@CNT/CNT/RC and TPBT@rGO/rGO/RC films. The TPBT@CNT/CNT/RC film-based electrode exhibited superior capacitive performance due to its uniform composition, achieving a specific capacitance of 1288.26 F/g at 0.5 A/g. In contrast, the TPBT@rGO/rGO/RC film-based electrode showed a lower capacitance of 398.75 F/g at 0.5 A/g, attributed to the uneven material distribution. Both composite film-based electrodes demonstrated excellent cycling stability, retaining 85.87 and 81.82% of their initial capacitance after 10,000 cycles, respectively. In a symmetric device configuration, the TPBT@CNT-50/CNT/RC (35/35/30, w/w) electrode achieved a specific capacitance of 84.32 F/g at 1 A/g, with a maximum energy density of 11.71 Wh/kg and a power density of 312.5 W/kg, while maintaining 77% of its initial capacitance after 10,000 cycles. These findings underscore the potential of TPBT-COF-based composites as sustainable, high-performance electrode materials for energy storage applications.