Porous carbon materials augmented with heteroatoms derived from hyperbranched biobased benzoxazine resins for enhanced CO₂ adsorption and exceptional supercapacitor performance

Porous carbon materials doped with heteroatoms are an excellent alternative for applications in CO2 adsorption and supercapacitors. Herein, we present a new approach to obtain heteroatoms (N, O, and S) doped porous carbon materials using bio-based hyperbranched benzoxazine (RES-HP-BZ) as a precursor. Two types of porous carbon materials, poly(RES-HP-BZ)-700 and poly(RES-HP-BZ)-800, were synthesized through a simple calcination method by carbonization and KOH activation of benzoxazine at temperatures of 700 degrees C and 800 degrees C, respectively. The chemical structure, texture properties, and surface chemistry characteristics were validated through FTIR, NMR, SEM, XRD, and XPS, respectively. The resulting poly(RES-HP-BZ)-800 exhibited micro and meso porous characteristics with a high SBET of 841 m2 g-1, pore size of 1.14 nm, and pore volume of 0.70 cm3 g-1. The poly(RES-HP-BZ)-800 also showed a high graphitization degree and electrochemically energetic N-6, N5, N-Q, O-2, and O-3 heteroatoms, which led to a high capacitance of 523 F g-1 (at 0.5 A g-1) as well as CO2 capture of 4.63 mmol g-1 at 298 K. These newly developed bio-based porous carbons derived from hyperbranched bio-benzoxazine with excellent electrochemical performance make them a promising candidate for eco-friendly supercapacitors.