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 applications 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 urgent 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 °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.