Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576.
Nano Lett. 2010 Dec 8;10(12):4844-50. doi: 10.1021/nl102445x. Epub 2010 Oct 28.
We report a method to synthesize tubular graphene structures by chemical vapor deposition (CVD) on Ni nanowire templates, using ethylene as a precursor at growth temperature of around 750 °C. Unlike carbon nanotubes that are synthesized via conventional routes, the number of graphene layers is determined by the growth time and is independent of the tube diameter and tube length, which follow those of the nanowire template. This allows us to realize large-diameter tubes with shells comprising a few or many layers of graphene as desired. Thin graphene layers are observed to be highly crystalline, and of uniform thickness throughout the length of the nanowire. Raman analysis shows the presence of a small level of defects typical of CVD-grown graphene. The metallic core could be removed by chemical etching to result in a collapsed tube. Backgated field-effect transistor measurements were conducted on the collapsed graphene tube. This approach to the realization of tubular graphene offers new opportunities for graphene-based nanodevices.
我们报告了一种通过化学气相沉积（CVD）在 Ni 纳米线模板上合成管状石墨烯结构的方法，使用乙烯作为前体，生长温度约为 750°C。与通过传统途径合成的碳纳米管不同，石墨烯层的数量由生长时间决定，并且与管的直径和长度无关，管的直径和长度遵循纳米线模板的直径和长度。这使得我们能够实现具有所需层数的大直径管，其外壳由几层或多层石墨烯组成。观察到薄的石墨烯层具有高度的结晶性，并且在纳米线的整个长度上厚度均匀。拉曼分析表明存在典型的 CVD 生长石墨烯的少量缺陷。通过化学蚀刻可以去除金属芯，从而得到塌陷的管。对塌陷的石墨烯管进行了背栅场效应晶体管测量。这种管状石墨烯的实现方法为基于石墨烯的纳米器件提供了新的机会。
