N, S-codoped porous biochar derived from bagasse-based polycondensate for high-performance CO2 capture and supercapacitor

Abstract

The utilization of in-situ heteroatom doping and carbonization techniques to produce porous biochar from waste biomass sources has the potential to significantly enhance electrochemical and CO2 adsorption performance of supercapacitors. In this work, an initiative N, S-codoped biochar was prepared through carbonation and KOH-activated pyrolysis of bagasse-based polycondensate precursors, which were synthesized using sugarcane bagasse as a carbon source, 3-amino-5-methio-1,2,4-triazole as a nitrogen and sulfur source and triglycidyl isocyanurate (TGIC) as a cross-linker, for efficient CO2 capture and energy storage. Through comprehensive material characterization and testing of the electrochemical and CO2 adsorption performance of the N,S-codoped bagasse-based porous biochar (NSBPB), the results demonstrated that the mesoporeous structure and the N, S-codoping displayed a significant synergistic effect on electrochemical and CO2 adsorption properties. The optimized NSBPB-600-2 displayed a CO2 adsorption capacity of 3.76 mmol g−1, and no significant decrease in adsorption capacity was observed over consecutive ten cycles. Moreover, the NSBPB-600-2 electrode delivered a specific capacitance of 217F g−1, and the NSBPB-600-2 symmetric supercapacitor exhibited a energy density of 13 Wh·kg−1. This approach invoving in-situ heteroatom doping of porous carbon materials using clean biomass carbon sources not only offers the advantages of simplicity, environmental friendliness and low cost, but also holds great potential for applications in CO2 capture and separation, as well as in supercapacitors.