- Title
- Formation of hollow carbon nanofibers on bio-char during microwave pyrolysis of palm kernel shell
- Creator
- Omoriyekomwan, Joy Esohe; Tahmasebi, Arash; Zhang, Jian; Yu, Jianglong
- Relation
- Energy Conversion and Management Vol. 148, Issue September 2017, p. 583-592
- Publisher Link
- http://dx.doi.org/10.1016/j.enconman.2017.06.022
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2017
- Description
- Hollow carbon nanofibers (HCNFs) were found to have formed during microwave pyrolysis of palm kernel shell (PKS) at 500 and 600 °C. The formation of HCNFs was only observed during microwave pyrolysis and not the fixed-bed pyrolysis, indicating that microwave played a key role in formation of HCNFs. X-ray diffraction (XRD) analysis of microwave bio-chars showed typical carbon diffractions at 2θ = 26.3° and 43.2°, indicating good graphitic structure of HCNFs, especially for bio-chars prepared at 600 °C. High resolution transmission electron microscope (HRTEM) results revealed multiwall nature of the HCNFs with carbon layer spacing of 0.34 nm. Two major tubular and bamboo-shape structures were observed for HCNFs. With increasing microwave pyrolysis temperature from 500 to 600 °C, the yield of HCNFs increased from 5.85 wt.% to 9.88 wt.%. Raman spectroscopy analysis showed that with increasing pyrolysis temperature to 600 °C, the ID/IG ratio decreased from 0.95 to 0.86, indicating higher order of the carbon layers of the HCNFs. Energy dispersive X-ray spectroscopy (EDS) showed the presence of Fe, K, and Ca in HCNFs structure which may have played a catalytic role during their formation and growth. Mechanism of formation and growth of HCNFs under microwave irradiation were proposed and discussed. The HCNFs-coated bio-char has great potential for removal of heavy metals from waste water.
- Subject
- hollow carbon nanofibers; microwave irradiation; bio-char; carbon structure
- Identifier
- http://hdl.handle.net/1959.13/1352409
- Identifier
- uon:30879
- Identifier
- ISSN:0196-8904
- Language
- eng
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