Robust reduction of graphene fluoride using an electrostatically biased scanning probe
Robust reduction of graphene fluoride using an electrostatically biased scanning probe
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DOI：
10.1007/s12274-013-0355-1
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发表时间：
2013-10-01
期刊：
影响因子：
9.9
通讯作者：
Lyuksyutov, Sergei F.
中科院分区：
文献类型：
--
作者：
Lee, Woo-Kyung;Tsoi, Stanislav;Lyuksyutov, Sergei F.
我们报告了一种新颖且易于使用的方法，利用原子力显微镜 (AFM) 尖端和 GF 基板之间产生的高静电场，以纳米级精度化学还原氟化石墨烯 (GF) 片。通过电场还原氟产生宽度为 105-1,800 nm 的石墨烯纳米带 (GNR)，其薄层电阻率从 > 1 T Omega 中心点 sq.(-1) (GF) 大幅降低至 46 k Omega 中心点 sq.(-1) (GNR)。氟的减少还改变了 GF 的形貌、摩擦力和功函数。开尔文探针力显微镜测量表明，GF 的功函数比石墨烯大 180-280 meV。通过在 1.2 μm 中心点 s(-1) 和 12 μm 中心点 s(-1) 之间改变 AFM 探针速度以及在 -8 和 -12 V 之间施加到样品的偏置电压来优化还原过程。从碳中去除氟所需的静电场类似于 1.6 V 中心点 nm(-1)。氟的减少可能是由于在这个强场中C-F键的软化或者由于外来水在弯液面中的积累和水解。
We report a novel and easily accessible method to chemically reduce graphene fluoride (GF) sheets with nanoscopic precision using high electrostatic fields generated between an atomic force microscope (AFM) tip and the GF substrate. Reduction of fluorine by the electric field produces graphene nanoribbons (GNR) with a width of 105-1,800 nm with sheet resistivity drastically decreased from > 1 T Omega center dot sq.(-1) (GF) down to 46 k Omega center dot sq.(-1) (GNR). Fluorine reduction also changes the topography, friction, and work function of the GF. Kelvin probe force microscopy measurements indicate that the work function of GF is 180-280 meV greater than that of graphene. The reduction process was optimized by varying the AFM probe velocity between 1.2 mu m center dot s(-1) and 12 mu m center dot s(-1) and the bias voltage applied to the sample between -8 and -12 V. The electrostatic field required to remove fluorine from carbon is similar to 1.6 V center dot nm(-1). Reduction of the fluorine may be due to the softening of the C-F bond in this intense field or to the accumulation and hydrolysis of adventitious water into a meniscus.