Direct conversion of biomass to nanoporous activated biocarbons for high CO2 adsorption and supercapacitor applications

Abstract A series of nanoporous activated biocarbons have been successfully obtained from novel carbon precursor lumpy bracket. The textural properties of the biocarbons were tailored towards microporosity suitable for high CO2 adsorption. At the temperature of 298 K and at the pressure of 0.15 bar outstanding CO2 adsorption up to 1.67 mmol/g was achieved. The performance of biocarbons in the absorption/regeneration cycles towards CO2 adsorption remained stable. The selectivity of CO2 over N2 calculated on the basis of Ideal Adsorbed Solution Theory was excellent (33.9–130.2). To the best to our knowledge, the prepared activated carbon labelled as 850_1 is one of the most promising sorbents tested in CO2 post-combustion capturing and pre-combustion capturing. Furthermore, the electrochemical properties of this sample were also evaluated. The specific capacitance reached over 220 F/g with excellent retention (nearly 92% of the original capacitance) after 5000 cycles. These results clearly indicate that activated carbons obtained from lumpy bracket can be used for the production of low cost and, more importantly, highly efficient electrode in supercapacitors as well. In this way, simple and efficient direct conversion of the lumpy bracket into the highly valuable multifunctional system is proposed.