Loading…

Studies on preparation and applications of polymeric precursor-based activated hard carbons: I. Activation mechanism and microstructure analyses

This study examined the influence of CO2 activation on pore characteristics and crystalline structures in the preparation of activated hard carbons (ACs). Changes in pore characteristics (specific surface area, total pore volume, mesopore volume) under varying conditions were analyzed using the Brun...

Full description

Saved in:
Bibliographic Details
Published in:Microporous and mesoporous materials 2016-01, Vol.219, p.258-264
Main Authors: Baek, Jin, Lee, Hye-Min, Roh, Jae-Seung, Lee, Hae-Seong, Kang, Hong Seok, Kim, Byung-Joo
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This study examined the influence of CO2 activation on pore characteristics and crystalline structures in the preparation of activated hard carbons (ACs). Changes in pore characteristics (specific surface area, total pore volume, mesopore volume) under varying conditions were analyzed using the Brunauer–Emmett-Teller (BET), Horváth-Kawazoe (HK), and Barrett-Joyner–Halenda (BJH) equations based on the adsorption isotherm (N2/77 K). X-ray diffraction (XRD) was employed to calculate the interplanar distance of crystalline structures, crystal size, and crystal diameter. As activation time increased during the CO2 activation process, the specific surface area surged from 50 to 2030 m2/g, and the total pore volume surged from 0.03 to 0.85 cm3/g. In particular, with an activation time of 60 min, the volume of mesopores increased rapidly to 0.10 cm3/g (250% increase compared to volume at 50 min). The interplanar distance of the (002) peak, crystal size, and crystal diameter varied in the range of 3.68∼3.51 Å, 9.40∼8.98 Å, and 29.87∼35.81, respectively. The oxidation of amorphous carbon atoms led to a decrease in interplanar distance and crystal size. As oxidation time increased, small-sized crystals also became oxidized, which resulted in an increase in crystal diameter and mesopore volume. [Display omitted] •The pore development mechanism of polymer-based activated carbons has been revealed.•The La increased by small crystal oxidation, resulting in increase in micropores.•The SBET were dramatically enhanced from 50 to 2030 m2/g.•Further oxidation led to the increase in mesopores by medium crystal demolition.
ISSN:1387-1811
1873-3093
DOI:10.1016/j.micromeso.2015.07.003