One-pot synthesis of potassium benzoate-derived porous carbon for CO2 capture and supercapacitor application

Abstract

Porous carbons are becoming increasingly fascinating materials for CO2 adsorption and supercapacitor appli-cations thanks to their large surface areas, excess amount of presence, heteroatom-decorated surface and cost-effectiveness. However, the harsh and corrosive preparation process limits their wide utilization, thus it is ur-gent to find out facile, one-step and non-corrosive approaches. Herein, the potassium benzoate was used to synthesize porous carbons by a single-step and self-activating approach. As-prepared carbons exhibit advanced textural activity, the Brunauer-Emmett-Teller (BET) surface area of these samples can be up to 1119 m2/g along with maximum pore volume of 0.56 cm3/g. Benefiting from such merits, optimal sample PBC-750-800 illustrates a high CO2 uptake of 3.59 and 4.91 mmol g-1 at 1 bar at 25 and 0 degrees C, respectively. Moreover, the PBC-750-800 exhibited cycling stability with 100 % retention of the initial CO2 adsorption capacity over 5 cycles together with an CO2/N2 selectivity of 18. Upon electrochemical characterization, the best PBC-750-800 sample showed a rather high specific capacitance of 320 F g-1 at a current density of 0.5 A g-1 and a good rate capability (57 % and 51 % capacitance retention at 5 and 30 A g-1 , respectively) at 6 M KOH electrolyte in a three-electrode system. The present study introduces a novel, cost-effective strategy to prepare advanced porous carbon for use in efficient CO2 adsorbent and supercapacitor applications.