†Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 305-701, Republic of Korea.
‡Graduate School of EEWS, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea.
ACS Nano. 2015 Apr 28;9(4):3814-9. doi: 10.1021/nn506755p. Epub 2015 Apr 2.
We report on the physical and chemical properties of atomic steps on the surface of highly oriented pyrolytic graphite (HOPG) investigated using atomic force microscopy. Two types of step edges are identified: internal (formed during crystal growth) and external (formed by mechanical cleavage of bulk HOPG). The external steps exhibit higher friction than the internal steps due to the broken bonds of the exposed edge C atoms, while carbon atoms in the internal steps are not exposed. The reactivity of the atomic steps is manifested in a variety of ways, including the preferential attachment of Pt nanoparticles deposited on HOPG when using atomic layer deposition and KOH clusters formed during drop casting from aqueous solutions. These phenomena imply that only external atomic steps can be used for selective electrodeposition for nanoscale electronic devices.
我们报告了使用原子力显微镜研究高取向热解石墨（HOPG）表面原子台阶的物理和化学性质。确定了两种类型的台阶边缘：内部（在晶体生长过程中形成）和外部（通过大块 HOPG 的机械劈裂形成）。由于暴露边缘 C 原子的断裂键，外部台阶的摩擦比内部台阶高，而内部台阶中的碳原子没有暴露。原子台阶的反应性表现在多种方式中，包括在使用原子层沉积时沉积在 HOPG 上的 Pt 纳米颗粒的优先附着以及在从水溶液滴铸时形成的 KOH 团簇。这些现象表明，只有外部原子台阶可用于纳米级电子器件的选择性电沉积。
