Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7606411 | Journal of Analytical and Applied Pyrolysis | 2018 | 7 Pages |
Abstract
Hollow carbon nanofibers (HCNFs) were formed on the bio-char surface during microwave pyrolysis of pine nut shell in the temperatures range of 400-700â¯Â°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 500â¯Â°C and 600â¯Â°C had a diameter of about 400â¯nm and length of 1400-5000â¯nm. HCNFs had multi-walled structure with a d-spacing of about 0.35â¯nm. Unlike fixed-bed bio-chars, the X-ray diffraction (XRD) analysis of the microwave bio-chars showed typical graphite peak at around 2θâ¯=â¯26.3° with the strongest peak observed in 600â¯Â°C bio-char. Raman spectroscopy analysis revealed that the highest degree of carbon order of HCNFs was achieved at 600â¯Â°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.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Jian Zhang, Arash Tahmasebi, Joy Esohe Omoriyekomwan, Jianglong Yu,