Lee Hyunsoo, Kim Kyoungsoo, Kang Seoung-Hun, Kwon Yonghyun, Kim Jong Hun, Kwon Young-Kyun, Ryoo Ryong, Park Jeong Young
Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 34141, South Korea.
Department of Chemistry, Chonbuk National University, Jeonju, Jeollabuk-do, 54896, South Korea.
Sci Rep. 2017 Sep 13;7(1):11460. doi: 10.1038/s41598-017-11602-5.
We report the remarkably high electrical conductance of microporous 3D graphene-like carbons that were formed using lanthanum (La)-catalyzed synthesis in a Y zeolite (LaY) template investigated using conductive atomic force microscopy (C-AFM) and theoretical calculations. To uncover the relation between local electrical conductance and the microporous structures, we tuned the crystallographic ordering of LaY-templated carbon systems by changing the heating temperature. The structure of the LaY-templated carbon prepared at the higher temperature has graphene-like sp hybridized bonds, which was confirmed using high-resolution transmission electron microscopy and X-ray diffraction measurements. C-AFM current-voltage spectroscopy revealed that the local current flow in the LaY-templated carbon depends on the quantity of C-C bonds within the narrow neck between the closed supercages (i.e. there are three types of carbon: carbon with heat treatment, carbon without heat treatment, and carbon synthesized at low temperature). The difference in electrical conductance on the LaY-templated carbon was also confirmed via theoretical computation using the Boltzmann transport theory and the deformation potential theory based on the density functional theory. These results suggest that the degree of order of the pores in the 3D zeolite-templated carbon structures is directly related to electrical conductance.
我们报道了使用镧（La）催化合成法在Y型沸石（LaY）模板中形成的微孔三维类石墨烯碳具有极高的电导率，该研究采用导电原子力显微镜（C-AFM）和理论计算。为了揭示局部电导率与微孔结构之间的关系，我们通过改变加热温度来调整LaY模板碳体系的晶体有序性。在较高温度下制备的LaY模板碳的结构具有类石墨烯的sp杂化键，这通过高分辨率透射电子显微镜和X射线衍射测量得到证实。C-AFM电流-电压光谱表明，LaY模板碳中的局部电流流动取决于封闭超笼之间狭窄颈部内C-C键的数量（即存在三种类型的碳：经过热处理的碳、未经过热处理的碳以及在低温下合成的碳）。基于密度泛函理论，利用玻尔兹曼输运理论和形变势理论通过理论计算也证实了LaY模板碳上电导率的差异。这些结果表明，三维沸石模板碳结构中孔的有序程度与电导率直接相关。
