Environmental remediation by microporous carbon: An efficient contender for CO2 and methylene blue adsorption. (December 2019)

• Record Type: Journal Article
• Authors: Rehman, Adeela; Park, Soo-Jin
• Is Part Of: Journal of CO₂ utilization. Volume 34(2019)
• Page Start: 656
• Page End: 667
• Publication Date: 2019-12
• Subjects: One-step condensation -- Ultra-microporous carbons -- CO2 adsorption -- Methylene blue adsorption -- Environmental remediation; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2019.08.015
• Languages: English
• ISSNs: 2212-9820

Abstract

Graphical abstract: Highlights: Microporous carbons were synthesized using solvent-free approach. The material exhibits CO2 uptake of 197 mg/g at 273 K and 1 bar. The prepared sample exhibit highest dye adsorption, 134.7 mg/g for an initial methylene blue concentration of 25 × 10 −2 mM. Abstract: Nitrogen-doped microporous carbons with extremely narrow pore size distribution were derived from sucrose and melamine with the molten LiCl/KCl salts acting as a template to generate pores. A high CO2 uptake of up to 197 mg/g at 273 K and 1 bar was observed, revealing the significance of the pore size (0.84 nm) for CO2 capture. Our findings demonstrate that the nitrogen-doped SMLK-1 has a large surface area (951 m 2 /g) and large micropore volume (0.42 cm 3 /g) with high nitrogen-content (11.2 at.%), but the adsorption capacity (180 mg/g at 273 K, 1 bar) is comparable to that of un-doped SMLK-0 ( S BET = 520 m 2 /g, V micro = 0.26 cm 3 /g). The CO2 uptake capacity per pore volume and volume fraction of the pores (<0.84 nm) in total pore volume exhibit a straight-line graph with a high correlation coefficient of 0.93 revealing that the adsorption capacity of the carbonaceous adsorbents may strongly rely upon the fine pore size distributions. Moreover, the prepared materials were also investigated as adsorbents for methylene blue from an aqueous solution. The sample with a melamine-to-sucrose ratio of 0 (SMLK-0) exhibited the excellent dye adsorption, 134.7 mg/g for an initial methylene blue concentration of 25 × 10 −2 mM and 31.1 mg/g for an initial concentration of 5 × 10 −2 mM. Therefore, the fabrication method presented here permits the fine-tuning of the pore network to exploit the prepared materials both as CO2 and dye adsorbents for environmental remediation.