Rosmi Mohamad Saufi, Yusop Mohd Zamri, Kalita Golap, Yaakob Yazid, Takahashi Chisato, Tanemura Masaki
Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
1] Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan [2] Department of Materials, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia.
Sci Rep. 2014 Dec 19;4:7563. doi: 10.1038/srep07563.
Control synthesis of high quality large-area graphene on transition metals (TMs) by chemical vapor deposition (CVD) is the most fascinating approach for practical device applications. Interaction of carbon atoms and TMs is quite critical to obtain graphene with precise layer number, crystal size and structure. Here, we reveal a solid phase reaction process to achieve Cu assisted graphene growth in nanoscale by in-situ transmission electron microscope (TEM). Significant structural transformation of amorphous carbon nanofiber (CNF) coated with Cu is observed with an applied potential in a two probe system. The coated Cu particle recrystallize and agglomerate toward the cathode with applied potential due to joule heating and large thermal gradient. Consequently, the amorphous carbon start crystallizing and forming sp(2) hybridized carbon to form graphene sheet from the tip of Cu surface. We observed structural deformation and breaking of the graphene nanoribbon with a higher applied potential, attributing to saturated current flow and induced Joule heating. The observed graphene formation in nanoscale by the in-situ TEM process can be significant to understand carbon atoms and Cu interaction.
通过化学气相沉积（CVD）在过渡金属（TMs）上控制合成高质量大面积石墨烯是实际器件应用中最具吸引力的方法。碳原子与过渡金属的相互作用对于获得具有精确层数、晶体尺寸和结构的石墨烯至关重要。在此，我们通过原位透射电子显微镜（TEM）揭示了一种固相反应过程，以实现纳米级铜辅助的石墨烯生长。在双探针系统中施加电势时，观察到涂覆有铜的非晶碳纳米纤维（CNF）发生了显著的结构转变。由于焦耳热和大的热梯度，涂覆的铜颗粒在施加电势时向阴极重结晶并团聚。因此，非晶碳开始结晶并形成sp(2)杂化碳，从铜表面的尖端形成石墨烯片。我们观察到在较高的施加电势下石墨烯纳米带的结构变形和断裂，这归因于饱和电流流动和诱导的焦耳热。通过原位TEM过程在纳米尺度上观察到的石墨烯形成对于理解碳原子与铜的相互作用可能具有重要意义。
