PlumX Metrics
Embed PlumX Metrics

Adsorption of metal ions on nitrogen surface functional groups in activated carbons

Langmuir, ISSN: 0743-7463, Vol: 18, Issue: 2, Page: 470-478
2002
  • 296
    Citations
  • 0
    Usage
  • 152
    Captures
  • 0
    Mentions
  • 0
    Social Media
Metric Options:   Counts1 Year3 Year

Metrics Details

  • Citations
    296
    • Citation Indexes
      295
    • Patent Family Citations
      1
      • Patent Families
        1
  • Captures
    152

Article Description

A commercially available coconut-shell-derived active carbon was oxidized with nitric acid, and both the original and oxidized active carbons were treated with ammonia at 1073 K to incorporate nitrogen functional groups into the carbon. An active carbon with very high nitrogen content (∼9.4 wt % daf) was also prepared from a nitrogen-rich precursor, polyacrylonitrile (PAN). These nitrogen-rich carbons had points of Zero charge (pH) similar to H-type active carbons. X-ray absorption near-edge structure (XANES) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and temperature-programmed desorption (TPD) were used to characterize the nitrogen functional groups in the carbons. The nitrogen functional groups present on the carbon surface were pyridinic, pyrrolic (or indolic), and pyridonic structures. The adsorption of transition metal cations Cd, Ni, and Cu from aqueous solution on the suite of active carbons showed that adsorption was markedly higher for carbons with nitrogen functional groups present on the surface than for carbons with similar pH values. In contrast, the adsorption characteristics of Ca from aqueous solution were similar for all the carbons studied. Flow microcalorimetry (FMC) studies showed that the enthalpies of adsorption of Cd(aq) on the active carbons with high nitrogen contents were much higher than for nitric acid oxidized carbons studied previously, which also had enhanced adsorption characteristics for metal ion species. The enthalpies of adsorption of Cu were similar to those obtained for Cd for specific active carbons. The nitrogen functional groups in the carbons act as surface coordination sites for the adsorption of transition metal ions from aqueous solution. The adsorption characteristics of these carbons are compared with those of oxidized carbons.

Bibliographic Details

Y. F. Jia; B. Xiao; K. M. Thomas

American Chemical Society (ACS)

Materials Science; Physics and Astronomy; Chemistry

Provide Feedback

Have ideas for a new metric? Would you like to see something else here?Let us know