Angstrom-resolved metal-organic framework-liquid interfaces

Metal-organic frameworks (MOFs) are a class of crystalline materials with a variety of applications in gas storage, catalysis, drug delivery or light harvesting. The optimization of those applications requires the characterization of MOF structure in the relevant environment. Dynamic force microscopy has been applied to follow dynamic processes of metal-organic-framework material. We provide images with spatial and time resolutions, respectively, of angstrom and seconds that show that Ce-RPF-8 surfaces immersed in water and glycerol experience a surface reconstruction process that is characterized by the diffusion of the molecular species along the step edges of the open terraces. The rate of the surface reconstruction process depends on the liquid. In water it happens spontaneously while in glycerol is triggered by applying an external force.We thank the financial support from the European Research Council ERC – AdG – 340177 (3DNanoMech) and the Ministerio de Economía y Competitividad (MINECO) (MAT2016-76507-R, MAT2013-44858-R, MAT2016-78465-R, and CTQ2014-61748-EXP). F.G. acknowledges financial support by MINECO (Programa Ramón y Cajal)