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 CO 2 , H 2 adsorption. The material prepared at 800 C presented the highest electrochemical performance with a specific capacitance of 300 F g À1 at 1 A g À1 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 CO 2 and H 2 . The functionalized carbon showed a good H 2 uptake value of 2.8 wt% under 1 bar pressure at 77 K. CO 2 uptake capacities were found to be 5.6 and 3.3 mmol g À1 at 1 bar pressure under the temperature of 273 and 298 K, respectively with a good CO 2 /N 2 selectivity of 14.36 and CO 2 /CH 4 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.

Rational Design of Sulfur-Doped Carbon with Expanded Inter-layer Spacing toward Anode Material of Sodium-Ion Batteries

“…CC and C–C bonding were seen in the C 1s XPS spectra at 284.1 and 285.0 eV, respectively, while C–S and CO bonding were verified at the higher binding energy levels with peak positions of 286 and 288 eV . The S 2p spectrum was separated into three peaks: two major peaks located at 163.37 and 164.64 eV correspond to S 2p 3/2 and S 2p 1/2 peaks of the covalent C–S bond of thiophene-type sulfur because of the spin–orbit coupling, and a broad peak located at 167.8 eV is assigned to the C-(SOx)-C bond. , Additionally, using CHNS analysis, it was shown that the proportion (weight %) of S in the carbon framework reduced from 9.6 for CS-1000 to 5.5 for CS-1100 and 3.25 for CS-1200, respectively. The elimination of sulfur-containing groups via high-temperature annealing is what caused the percentage fall in the sulfur concentration .…”

“…A broad peak centered at roughly 2θ = 24.9° corresponds to (200) graphite planes, whereas another peak centered at roughly 2θ of 43.5° corresponds to (100) graphite planes . The wide diffraction peaks show that CSs have a low degree of crystallinity . Furthermore, the graphitic layer spacing for CSs derived from (002) peaks using the Bragg equation was around 0.36 nm.…”

“…27 The wide diffraction peaks show that CSs have a low degree of crystallinity. 28 Furthermore, the graphitic layer spacing for CSs derived from (002) peaks using the Bragg equation was around 0.36 nm. The (002) peak generally grows sharper and moves toward higher 2θ values with the rise in carbonization temperature, resulting in decreased inter-layer spacing.…”

Constructing micropore‐rich nitrogen‐doped carbon for high‐performance supercapacitor and adsorption of carbon dioxide

“…Also the symmetrical nature of the GCD plots show good reversibility of electrochemical performance. 36 The C s values were calculated from the GCD curves in the current range of 1 to 10 A g À1 as depicted in Figure 4C. The C s value for 1 A g À1 of current density was obtained to be nearly 200 F g À1 while those values for current densities of 2, 3, 4, 5, 7, and 10 A g À1 are found to be 184, 174, 168, 160, 154, and 150 F g À1 , respectively.…”

“…The GCD diagrams as depicted in the Figure 4B exhibit linear shape in the charge‐discharge profiles indicating the EDLC type capacitive behaviour. Also the symmetrical nature of the GCD plots show good reversibility of electrochemical performance 36 . The C s values were calculated from the GCD curves in the current range of 1 to 10 A g −1 as depicted in Figure 4C.…”