Surinlert Piyaporn, Kokmat Phurida, Ruammaitree Akkawat
Chulabhorn International College of Medicine, Thammasat University Pathum Thani 12120 Thailand.
Thammasat University Research Unit in Synthesis and Applications of Graphene, Thammasat University Pathum Thani 12120 Thailand.
RSC Adv. 2022 Sep 2;12(38):25048-25053. doi: 10.1039/d2ra02686d. eCollection 2022 Aug 30.
Monolayer graphene has excellent electrical properties especially a linear dispersion in the band structure at the -point in the Brillouin zone. However, its electronic transport properties can be degraded by surface roughness and attachment of charge impurities. Although multilayer graphene can reduce the surface roughness and attachment of charge impurities, the increase in the number of graphene layers can degrade the electronic transport properties due to interlayer interactions. Turbostratic graphene can significantly reduce the effect of interlayer interaction of multilayer graphene resulting in electrical properties similar to those of monolayer graphene. In this report, we have demonstrated the growth of turbostratic stacked graphene using waste ferric chloride solution as a feedstock by vaporization and calcination at 700 °C for 6 hours under an argon atmosphere. SEM images and EDX elemental distribution maps showed graphene can be grown on iron and nickel catalysts. XRD results and Raman spectra confirmed the presence of turbostratic stacked graphene with the interlayer spacing in the range of 3.41 Å to 3.44 Å. The Raman spectra in all samples also displayed a weak intensity peak of iTALO and a well-fitted 2D band by a single Lorentzian peak indicating the presence of turbostratic stacked graphene. In addition, XPS spectra reveal the growth mechanism of the turbostratic stacked graphene. This synthesis process of turbostratic stacked graphene is not only simple, low-cost, and suitable for large-scale production but also decreases the environmental issues from releasing waste ferric chloride solution with improper disposal.
单层石墨烯具有优异的电学性能，特别是在布里渊区Γ点的能带结构中具有线性色散。然而，其电子输运性能会因表面粗糙度和电荷杂质的附着而降低。尽管多层石墨烯可以降低表面粗糙度和电荷杂质的附着，但由于层间相互作用，石墨烯层数的增加会降低电子输运性能。乱层石墨烯可以显著降低多层石墨烯层间相互作用的影响，从而产生与单层石墨烯相似的电学性能。在本报告中，我们展示了以废氯化铁溶液为原料，通过在氩气气氛下于700°C蒸发和煅烧6小时来生长乱层堆叠石墨烯。扫描电子显微镜（SEM）图像和能谱仪（EDX）元素分布图表明，石墨烯可以在铁和镍催化剂上生长。X射线衍射（XRD）结果和拉曼光谱证实了存在层间距在3.41 Å至3.44 Å范围内的乱层堆叠石墨烯。所有样品的拉曼光谱还显示出一个弱强度的iTALO峰和一个由单个洛伦兹峰很好拟合的2D带，表明存在乱层堆叠石墨烯。此外，X射线光电子能谱（XPS）揭示了乱层堆叠石墨烯的生长机理。这种乱层堆叠石墨烯的合成过程不仅简单、低成本且适合大规模生产，还减少了因不当处置废氯化铁溶液而产生的环境问题。
