Facile 1D graphene fiber synthesis from an agricultural by-product: A silicon-mediated graphenization route
| Autor: | Mauricio Terrones, Nigel A. Marks, Kazunori Fujisawa, Yu Lei, Carla de Tomas, Irene Suarez-Martinez, Masatsugu Fujishige, Kenji Takeuchi, Ana Laura Elías, Joshua A. Robinson, Morinobu Endo, Chanjing Zhou, Shruti Subramanian, Yu-Chuan Lin |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Silicon Graphene Carbonization Stacking Nanowire chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention symbols.namesake Molecular dynamics chemistry Chemical engineering law symbols General Materials Science Sublimation (phase transition) 0210 nano-technology Raman spectroscopy |
| Zdroj: | Carbon. 142:78-88 |
| ISSN: | 0008-6223 |
| Popis: | A one-dimensional (1D) graphene fiber with a novel structure has been prepared by a heat treatment of rice husk, a natural by-product that contains high amounts of silica. A step-by-step heat treatment of rice husk revealed that (i) carbonization yields porous carbon and silica, (ii) 1D β-SiC nanowires are formed by the carbothermic reduction of silica, (iii) finally 1D graphene fibers are created by silicon sublimation from 1D β-SiC nanowires. Raman spectroscopy and electron microscopy studies revealed that the graphene fiber is composed of a turbostratic multilayer structure. The SiC-derived material exhibits a large crystalline size and turbostratic stacking making each layer as quasi-free-standing graphene, which is confirmed by the 3.9 times higher Raman G′-band intensity over the G-band intensity. Molecular dynamics simulations revealed a high diffusion rate of Si atoms and a volume reduction of the SiC structure at the sublimation temperature. Since the silicon sublimation occurred from multiple points of the SiC nanowire, this led to radially-collapsed fibers and faceted structures with thick-graphitic-layer that are inter-connected (deflated-balloons and inter-connected balloon-like fibers). This facile synthesis route opens up a new avenue to the cost-effective and etching-free production of self-standing graphene for its bulk usage. |
| Databáze: | OpenAIRE |
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