The Application of Hollow Carbon Nanofibers Prepared by Electrospinning to Carbon Dioxide Capture

Abstract

Coaxial electrospinning has been considered a straightforward and convenient method for producing hollow nanofibers. Therefore, the objective of this study was to develop hollow activated carbon nanofibers (HACNFs) for CO2 capture in order to reduce emissions of CO2 to the atmosphere and mitigate global warming. Results showed that the sacrificing core could be decomposed at carbonization temperatures above 900 °C, allowing the formation of hollow nanofibers. The average outer diameters of HACNFs ranged from 550 to 750 nm, with a shell thickness of 75 nm. During the carbonization stage, the denitrogenation reactions were significant, while in the CO2 activation process, the release of carbon oxides became prominent. Therefore, the CO2 activation could increase the percentages of N=C and quaternary N groups. The major nitrogen functionalities on most samples were O=C–NH and quaternary N. However, =C and quaternary N groups were found to be crucial in determining the CO2 adsorption performance. CO2 adsorption on HACNFs occurred due to physical adsorption and was an exothermic reaction. The optimal CO2 adsorption performance was observed for HACNFs carbonized at 900 °C, where 3.03 mmol/g (1 atm) and 0.99 mmol/g (0.15 atm) were measured at 25 °C. The degradation of CO2 uptakes after 10 adsorption−desorption cyclic runs could be maintained within 8.9%.

Post-treatment strategies for pyrophoric KOH-activated carbon nanofibres

“…Both isosteric enthalpies of adsorption are comparable to adsorption enthalpies of activated electrospun carbon nanofibres in literature. 57 The more distinctive decrease of the isosteric enthalpy of adsorption for high O 2 -flow can be linked to a higher degree of surface oxygen due to the partial carbon oxidation at high O 2 -flow ( Table 1 ), which probably lowers the binding affinity towards CO 2 due to the increased number of acidic groups on the surface.…”

Rearranged Copolyurea Networks for Selective Carbon Dioxide Adsorption at Room Temperature

“…Porous organic networks have been studied for use as gas adsorbents [1][2][3][4][5][6][7], owing to their high surface area and microporosity [8,9], the tuneability of their organic chemical structures and microstructures for high adsorption efficiency, and selectivity to a targeted gas [1,[10][11][12]. Capturing carbon dioxide (CO 2 ) using organic porous materials has drawn particular attention [13,14], yielding many adsorbents that exhibit high adsorption quantity with selectivity.…”