The periodic bulk structures of metal–organic frameworks (MOFs) can be solved by diffraction-based techniques; however, their non-periodic local structures—such as crystal surfaces, grain boundaries, defects, and guest molecules—have long been elusive due to a lack of suitable characterization tools. Recent advances in (scanning) transmission electron microscopy ((S)TEM) has made it possible to probe the local structures of MOFs at atomic resolution. In this article, we discuss why high-resolution (S)TEM of MOFs is challenging and how the new low-dose techniques overcome this challenge, and we review various MOF structural features observed by (S)TEM and important insights gained from these observations. Our discussions focus on real-space imaging, excluding other TEM-related characterization techniques (e.g. electron diffraction and spectroscopy).
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This research was supported by CCF grant (FCC/1/1972-19) to Y.H. from King Abdullah University of Science and Technology (KAUST). Y.Z. acknowledges financial support from National Natural Science Foundation of China (21771161) and the Thousand Talents Program for Distinguished Young Scholars. D.Z. acknowledges financial support from Fundamental Research Funds for the Central Universities (02200052020013) and the Thousand Talents Program for Distinguished Young Scholars.