2017年2月20日,《Nature》(自然)子刊《Nature Materials》(自然·材料)发表了我校材料科学与工程学院郑斌博士的研究成果“Unravelling surface and interfacial structures of a metal-organic framework by transmission electron microscopy”(通过透射电子显微镜揭示金属-有机框架表面和界面结构)(DOI: 10.1038/nmat4852)。郑斌博士为为这篇研究成果论文的唯一国内学者,西安科技大学是唯一的国内单位。
《Nature Materials》是材料领域影响力最高的学术期刊,其2016年影响因子高达38.891。这是西安科技大学自1958年建校以来首次在《Nature Materials》 发表高水平学术论文。
下面是郑斌博士与与美国劳伦斯伯克利国家重点实验室和沙特阿卜杜拉国王科技大学合作完成的研究成果论文“Unravelling surface and interfacial structures of a metal-organic framework by transmission electron microscopy”(通过透射电子显微镜揭示金属-有机框架表面和界面结构)的英文摘要及中文译文:
Metal-organic frameworks (MOFs) are crystalline porous materials with designable topology, porosity and functionality, having promising applications in gas storage and separation, ion conduction and catalysis. It is challenging to observe MOFs with transmission electron microscopy (TEM) due to the extreme instability of MOFs upon electron beam irradiation. Here, we use a direct-detection electron-counting camera to acquire TEM images of the MOF ZIF-8 with an ultralow dose of 4.1 electrons per square ångström to retain the structural integrity. The obtained image involves structural information transferred up to 2.1 Å, allowing the resolution of individual atomic columns of Zn and organic linkers in the framework. Furthermore, TEM reveals important local structural features of ZIF-8 crystals that cannot be identified by diraction techniques, including armchair-type surface terminations and coherent interfaces between assembled crystals. These observations allow us to understand how ZIF-8 crystals self-assemble and the subsequent influence of interfacial cavities on mass transport of guest molecules.
金属-有机框架(MOFs)是结晶多孔材料,具有可设计拓扑性、孔隙率及功能性,在气体储存、离子传导及催化领域有广阔的应用前景。由于电子束照射时MOFs的极不稳定性,因此用透射电子显微镜(TEM)观察MOFs具有挑战性。我们使用直接检测电子数相机得到了每平方埃4.1超低量电子的MOFs ZIF-8 TEM图像,从而保持了结构的完整性。所获得的图像包含转移达2.1埃的结构信息,实现了框架中Zn单原子列和有机连体的分辨。此外,TEM还揭示了用diraction技术不能辨别的ZIF-8晶体的重要局部特征,包括扶手椅型表面终端以及组晶体之间的相干界面。这些观察使我们掌握了ZIF-8是如何自组以及界面空穴对客体分子质量传输的影响程度。