Nitrogen-Enriched Carbon Aerogels Derived from Polybenzoxazine Cross-Linked Graphene Oxide-Chitosan Hybrid Matrix with Superior CO₂ Capture Performance

Abstract

The present study reports advanced nitrogen-enriched carbon aerogels (N-CAs) that have been derived from the pyrolysis of polybenzoxazine cross-linked graphene oxide-chitosan aerogels. The role of the BZ chemical structure and the impact of KOH chemical activation of the obtained N-CAs on the BET specific surface area, porosity characteristics, and CO 2 adsorption capacity have been studied. The impact of the molecular structure of benzoxazine precursors on the CO 2 adsorption behavior has been investigated using two benzoxazines with different chemical forms, namely, main-chain type benzoxazine polymer MCBP(BAtepa) and star-like telechelic benzoxazine SLTB(4HBA-t403). The N-CA derived from the pyrolysis of GO-CTS-SLTB(4HBA-t403) exhibited a maximum 1218 ± 14 m 2 g −1 of BET surface area as well as a considerable total pore volume, micropore volume, and average pore diameter of 0.75 cm 3 g −1 , 0.65 cm 3 g −1 , and 0.87 nm, respectively. The investigations indicated that MCBP(BAtepa) was more favorable for CO 2 adsorption than SLTB(4HBA-t403). The N-CAs exhibited excellent adsorption selectivity of CO 2 from the CO 2 /N 2 mixture. The resultant N-CA from the pyrolysis of GO-CTS-MCBP(BA-tepa) aerogel at 800 °C showed a high CO 2 /N 2 selectivity of 17.7 ± 0.1 with an excellent reversible adsorption capacity of ∼6.1 mmol CO 2 g −1 at 25 °C and 100 kPa. Upon KOH activation of the N-CA, the CO 2 /N 2 selectivity increased to 21.3 ± 0.3, and a maximum adsorption capacity of ∼ 7.34 mmol CO 2 g −1 was obtained; thus, these types of N-CAs become one of the promising sorbents that have been recorded for significant CO 2 adsorption capacities in the literature.

Robust Nitrogen-Doped Microporous Carbon via Crown Ether-Functionalized Benzoxazine-Linked Porous Organic Polymers for Enhanced CO2 Adsorption and Supercapacitor Applications

“…Consequently, MCs are widely considered as excellent electrode materials for supercapacitors, demonstrating outstanding performance . PBZs also exhibit great potential for high-performance nitrogen-doped MCs due to their robust heat stability, high char yield, robust heat stability, and less shrinkage. , Moreover, the nitrogen (N) content in these materials could be modified by adjusting the amine percentage in the PBZs structure . Wan et al revealed that NPMCs with high O and N contents derived from BZ with CN groups showed a maximum capacitance of 362.4 F g –1 , along with an impressive retention rate of 94.7% …”