Synthesis of sulfur‐doped porous carbon for supercapacitor and gas adsorption applications

Abstract

Heteroatom-doped porous carbon materials have great potential for both capacitive energy storage and gas sorption applications. This article reports the synthesis of highly porous sulfur-doped carbon from thiophene using an in situ self-doping strategy followed by KOH activation. A series of highly porous sulfur-containing carbon materials with high surface area and pore volume were prepared through variation of activation temperature from 600°C to 900°C and applied as supercapacitor electrodes in alkaline as well as neutral electrolyte and also as adsorbent for CO2, H2 adsorption. The material prepared at 800°C presented the highest electrochemical performance with a specific capacitance of 300 F g−1 at 1 A g−1 in 6 M KOH because of its high surface area and pore volume. The presence of oxidized sulfur functionality, high surface area, and micro-mesoporous structure were the responsible factors for enhanced storage of gases like CO2 and H2. The functionalized carbon showed a good H2 uptake value of 2.8 wt% under 1 bar pressure at 77 K. CO2 uptake capacities were found to be 5.6 and 3.3 mmol g−1 at 1 bar pressure under the temperature of 273 and 298 K, respectively with a good CO2/N2 selectivity of 14.36 and CO2/CH4 selectivity of 2.53. This report presents a promising porous sulfur-doped carbon material for cost-effective and efficient gas adsorption and energy storage systems.