Abstract Few-layer graphene nano-flakes (GNFs) are successfully prepared via hydrocarbon pyrolysis using a non-thermal plasma process based on a magnetically stabilized gliding arc discharge (MSGAD) at atmospheric pressure. The effects of feedstock gas type and hydrogen flow rate on the morphology of carbon nanomaterials are investigated. When the hydrogen/carbon (H/C) molar ratio is 4, the synthesized GNFs consist of 10 layers per stack with dimensions between 100 and 300 nm in a 4.57.2% yield. The energy cost is 0.1–0.2 kWh/g, which makes this process feasible for large-scale GNFs production. The results show that appropriately increasing the H/C molar ratio promotes the morphological transformation of carbon nanomaterials from spherical carbon nanoparticles (SCNs) to GNFs, improve the quality of GNFs and reduce the stacking of graphite layers. However, increasing the H/C ratio reduces the yields of carbon nanomaterials, so as to increase the energy cost. Analysis suggests that increasing the H/C ratio reduces the concentration of polycyclic aromatic hydrocarbon (PAH) and generates more H atoms, which helps form a two-dimensional nucleation and promotes planar growth. However, an excessive H/C ratio may introduce some defects due to an etching effect.

中文翻译：

---

氢/碳摩尔比对非热等离子体法合成石墨烯纳米薄片的影响

摘要 使用基于大气压磁稳定滑动电弧放电 (MSGAD) 的非热等离子体工艺，通过碳氢化合物热解成功制备了少层石墨烯纳米薄片 (GNF)。研究了原料气体类型和氢气流速对碳纳米材料形貌的影响。当氢/碳 (H/C) 摩尔比为 4 时，合成的 GNF 由每个堆叠 10 层组成，尺寸在 100 到 300 nm 之间，产率为 4.57.2%。能源成本为 0.1-0.2 kWh/g，这使得该过程适用于大规模 GNF 生产。结果表明，适当增加H/C摩尔比可促进碳纳米材料从球形碳纳米粒子（SCNs）向GNFs的形态转变，提高GNFs的质量并减少石墨层的堆积。然而，提高H/C比会降低碳纳米材料的产率，从而增加能源成本。分析表明，增加 H/C 比会降低多环芳烃 (PAH) 的浓度并产生更多的 H 原子，这有助于形成二维成核并促进平面生长。然而，由于蚀刻效应，过高的 H/C 比可能会引入一些缺陷。