| 研究課題/領域番号 |
20J11624
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| 研究機関 | 大阪大学 |
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研究代表者 |
朱 陸亭 大阪大学, 工学研究科, 特別研究員(DC2)
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| 研究期間 (年度) |
2020-04-24 – 2022-03-31
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| キーワード | Chitin nanofiber paper / Electrical conductivity / 3D porous nanocarbon / Nitrogen doped carbon / Photo sensor / Supercapacitor / Laser writing |
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| 研究実績の概要 |
Biomasses from nature such as cellulose from wood and chitin from crustaceans are natural gifts for human beings due to the sustainability and renewability. However, the insulative property would restrict the availability in advanced applications, especially in electronic applications.
So I tried to modulate the electrical properties of chitin from crab shell by pyrolysis. With intrinsic nitrogen element of chitin, N-doped carbon (defective carbon) can be made by pyrolysis. When endowing a three-dimensional (3D) nanostructure of chitin, a 3D porous and defective nanocarbon was prepared after pyrolysis. Such pyrolyzed chitin with tunable electrical conductivity showed good performance as a photosensor and an energy-storage supercapacitor electrode, which would open a new door for future sustainable electronics. The relevant article "Pyrolyzed chitin nanofiber paper as a three-dimensional porous and defective nanocarbon for photosensing and energy storage" was published in Journal of Materials Chemistry C (Impact factor:7.08) and unexpectedly became a hot paper (DOI: 10.1039/d0tc05799a).
Moreover, I tried to apply laser writing method to convert biomass to carbon material. Compare with pyrolysis, laser writing shows the patternable and time-saving advantages. It proved to work well on cellulose paper by laser writing. With controlled laser power and laser speed, cellulose paper derived carbon had stepwise conductivity, which could be applied as electrodes in an all-cellulose derived humidity sensor.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
Following my research proposal, I achieved to make 3D porous and defective nanocarbon from chitin nanofiber paper that can control not only the electrical conductivity, but also the N-doping content and specific surface area. Therefore, it provides promising potential for a series of electronic applications. As a result, this pyrolyzed chitin nanofiber paper presented good performance as photosensor and energy-storage supercapacitor electrode. I published this part of work in Journal of Materials Chemistry C.
In addition, I attempted to use the laser writing method to convert biomass into carbon materials. Such carbons showed stepwise conductivity, thus providing the possibility for an all-cellulose derived humidity sensor. This part of work is in preparation as planned.
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| 今後の研究の推進方策 |
Laser writing to make carbon materials (Laser induced graphene/graphite) is a new research theme since it was first reported in 2014. The laser induces a photochemical and photothermal transition on substrates with a precision that is hard to achieve using traditional thermal approaches. Moreover, laser writing is patternable and efficient, which is able to achieve large-scale production for electronics.
However, laser writing of biomass still need more investigation since the formation of laser induced graphene/graphite is selective to different precursors, different laser sources (including different laser wavelength and continuous or pulsed laser) and laser atmospheres (ambient atmosphere or at inert gases). More specifically, a precursor with different functional groups also showed different performance. We found cellulose with original hydroxyl group can't form graphite, while by partially oxidizing the hydroxyl to carboxylate groups, it's easy to convert to graphite. How to control such conditions and what the mechanism is still require more efforts. So my future work will focus on the above points.
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