Spectroscopy and Microscopy on the Formation of Zeolitic Imidazolate Frameworks

Abstract

The field of metal organic frameworks (MOFs) thin-films, and its sub-family of ZIFs thin-films, possesses a lot of potential for increasing our fundamental understanding of materials synthesis and the related surface properties, which are created during the synthesis of these functional porous materials. Many new fabrication methods have been developed in the past years and most of these methods for the preparation of the thin-films stem from their bulk analogues. However, a detailed understanding of the chemistries governing the synthesis of ZIFs and their related thin-films is essential in order to 1) design new ZIFs with desired functionalities and 2) unlock their full potential for existing or new applications. In this PhD thesis, the main focus was devoted to the spectroscopy and microscopy on the formation of bulk as well as thin-films of ZIFs. Multiple spectroscopy and microscopy techniques were utilized in order to give insights into the influence of synthesis parameters on the thin-film properties, such as coverage/density, particle size and thickness as well as their influence on nucleation and growth for the thin-films as well as the impact of the coordination chemistry of the metal ions used. Furthermore, a powerful combination of AFM and vibrational spectroscopy technique(s) was utilized and a detailed data analysis of the Raman spectroscopy data was performed by PCA, while a vibrational spectroscopy data library was build up through DFT calculations providing insights into the presence of defects sites through several spectroscopic markers were obtained. The findings summarized in this PhD thesis are of importance in the field of ZIF thin-film research and can enable to design ZIFs with desired properties and further unlock their full potential.