- Title
- Direct synthesis of hollow carbon nanofibers on bio-char during microwave pyrolysis of pine nut shell
- Creator
- Zhang, Jian; Tahmasebi, Arash; Omoriyekomwan, Joy Esohe; Yu, Jianglong
- Relation
- Journal of Analytical and Applied Pyrolysis Vol. 130, Issue March 2018, p. 142-148
- Publisher Link
- http://dx.doi.org/10.1016/j.jaap.2018.01.016
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2018
- Description
- Hollow carbon nanofibers (HCNFs) were formed on the bio-char surface during microwave pyrolysis of pine nut shell in the temperatures range of 400–700 °C without the use of any additional catalyst, except activated carbon added as a microwave absorber. Scanning electron microscopy (SEM) analysis showed that HCNFs were only formed on microwave pyrolysis chars and not fixed-bed chars, suggesting that microwave irradiation had a major influence on their formation. High resolution transmission electron microscope (HRTEM) results showed that the synthesized HCNFs at 500 °C and 600 °C had a diameter of about 400 nm and length of 1400–5000 nm. HCNFs had multi-walled structure with a d-spacing of about 0.35 nm. Unlike fixed-bed bio-chars, the X-ray diffraction (XRD) analysis of the microwave bio-chars showed typical graphite peak at around 2θ = 26.3° with the strongest peak observed in 600 °C bio-char. Raman spectroscopy analysis revealed that the highest degree of carbon order of HCNFs was achieved at 600 °C, which agreed well with XRD analysis results. Detailed analysis of the volatiles evolved during microwave pyrolysis suggested that hydrocarbons in bio-oil such as benzene and alkenes and CO, CO2, methane, and ethane in bio-gas acted as the carbon source during formation of HCNFs.
- Subject
- hollow carbon nanofibers; bio-char; mircowave pyrolysis; carbon structure
- Identifier
- http://hdl.handle.net/1959.13/1466306
- Identifier
- uon:47503
- Identifier
- ISSN:0165-2370
- Language
- eng
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