Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, 61801, IL, USA.
Department of Material Science and Engineering, Seoul National University, Seoul, 08826, Korea.
Adv Mater. 2019 Sep;31(39):e1903424. doi: 10.1002/adma.201903424. Epub 2019 Aug 7.
A new compound material of 2D hydrofluorinated graphene (HFG) is demonstrated whose relative hydrogen/fluorine concentrations can be tailored between the extremes of either hydrogenated graphene (HG) and fluorinated graphene (FG). The material is fabricated through subsequent exposures to indirect hydrogen plasma and xenon difluoride (XeF ). Controlling the relative concentration in the HFG compound enables tailoring of material properties between the extremes offered by the constituent materials and in-plane patterning produces micrometer-scale regions with different surface properties. The utility of the technique to tailor the surface wettability, surface friction, and electrical conductivity is demonstrated. HFG compounds display wettability between the extremes of pure FG with contact angle of 95° ± 5° and pure HG with contact angle of 42° ± 2°. Similarly, the HFG surface friction may be tailored between the two extremes. Finally, the HFG electrical conductivity tunes through five orders of magnitude when transitioning from FG to HG. When combined with simulation, the electrical measurements reveal the mechanism producing the compound to be a dynamic process of adatom desorption and replacement. This study opens a new class of 2D compound materials and innovative chemical patterning with applications for atomically thin 2D circuits consisting of chemically/electrically modulated regions.
一种新的二维氢化氟化石墨烯（HFG）复合材料被展示出来，其相对的氢/氟浓度可以在氢化石墨烯（HG）和氟化石墨烯（FG）的极端之间进行调整。该材料是通过随后暴露于间接氢等离子体和氙二氟化物（XeF ）来制造的。控制 HFG 化合物中的相对浓度可以在组成材料提供的极端之间调整材料性能，并且面内图案化可以产生具有不同表面性能的微米级区域。该技术用于调整表面润湿性、表面摩擦和电导率的实用性得到了证明。HFG 化合物的润湿性在纯 FG 的极端之间，接触角为 95°±5°，在纯 HG 的极端之间，接触角为 42°±2°。类似地，HFG 表面摩擦也可以在两个极端之间进行调整。最后，当从 FG 过渡到 HG 时，HFG 的电导率可以调整五个数量级。通过与模拟相结合，电测量揭示了产生化合物的机制是吸附原子的解吸和替代的动态过程。这项研究开辟了一类新的二维化合物材料和创新的化学图案化，可应用于由化学/电调制区域组成的原子薄二维电路。
