Zhang Liyuan, Wang Meihui, Jeon Dongho, Meng Yongqiang, Lee Sun Hwa, Choe Myeonggi, Li Yunqing, Wang Mengran, Lu Sherilyn J, Lee Zonghoon, Seong Won Kyung, Ruoff Rodney S
Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea.
School of Metallurgy and Environment, Central South University, Changsha, China.
Nat Commun. 2025 Aug 12;16(1):7180. doi: 10.1038/s41467-025-62227-6.
Graphite films with large grain sizes have been reportedly obtained by using metal as catalysts, but the obtained graphite is mostly heavily wrinkled, thus containing defects that degrade its properties. We report the synthesis of mirror-like and large-grained graphite films with only a few nano kinks and controllable dimensions, achieved by using flat Ni-Mo alloy melts of the same lateral dimensions as the metal foils used to make this alloy melt. The graphite film exhibited few nano kinks and a mirror-like appearance because the deliberate evaporation of much of the Ni produced a porous substrate, which in turn dramatically weakened the substrate-graphite film interaction before cooling. The mirror-like graphite appears to be 100% AB-stacked with millimeter-sized grains that are much larger than the multi-micron grain size of highly oriented pyrolytic graphite and rivaled in size only by a small percentage of natural graphite. Our graphite films have an electrical conductivity of 2.25 × 10 S cm at 300 K. Tensile loading of macroscale samples showed an average Young's modulus of 969 ± 69 GPa and average fracture strength of 1.29 ± 0.203 GPa, and Frequency Domain Thermoreflectance revealed an average in-plane thermal conductivity of 2034.4 ± 68 W m·K.
据报道，通过使用金属作为催化剂可获得具有大晶粒尺寸的石墨薄膜，但所获得的石墨大多有严重的褶皱，因此含有会降低其性能的缺陷。我们报告了通过使用与用于制造该合金熔体的金属箔具有相同横向尺寸的扁平镍钼合金熔体，合成出仅具有少量纳米扭结且尺寸可控的镜面状大晶粒石墨薄膜。该石墨薄膜呈现出少量纳米扭结和镜面外观，这是因为大量镍的有意蒸发产生了多孔衬底，这反过来又在冷却前极大地削弱了衬底与石墨薄膜之间的相互作用。这种镜面状石墨似乎是100% AB堆叠的，其毫米级晶粒比高度取向热解石墨的多微米晶粒尺寸大得多，仅在尺寸上可与一小部分天然石墨相媲美。我们的石墨薄膜在300 K时的电导率为2.25×10 S/cm。对宏观样品进行拉伸加载显示，平均杨氏模量为969±69 GPa，平均断裂强度为1.29±0.203 GPa，频域热反射法测得面内热导率平均为2034.4±68 W/(m·K)。
