Decoding Nucleation and Growth of Zeolitic Imidazolate Framework Thin Films with Atomic Force Microscopy and Vibrational Spectroscopy

Abstract

The synthesis of metal‐organic framework (MOF) thin films has garnered significant attention during the past decade. By better understanding the parameters governing the nucleation and growth of such thin films, their properties can be rationally tuned, empowering their application as (reactive) membranes. Here, a combined AFM‐vibrational spectroscopy research strategy is employed to detail the chemistries governing the nucleation and growth of zeolitic imidazolate framework (ZIF) thin films, in particular isostructural Co‐ZIF‐67 and Zn‐ZIF‐8. First, a single step direct synthesis approach is used to investigate the influence of different synthesis parameters –metal/linker ratio, temperature, and metal type– on the thin film nucleation and growth behaviour. While the metal/linker ratio has a pronounced effect on the thin film nucleation rate, the temperature mainly influences the growth kinetics of nuclei forming the thin film. In addition, the nucleation and growth of ZIF thin films is shown to be highly dependent on the electronegativity of the metal type. Thin‐film thickness control can be achieved by using a multistep synthesis strategy, implying repetitive applications of single step deposition under identical synthesis conditions, for which a growth mechanism is proposed. This study provides insight into the influence of synthesis parameters on the ZIF thin film properties, using tools at hand to rationally tune MOF thin film properties.

Incorporating Metal Organic Frameworks within Microstructured Optical Fibers toward Scalable Photoreactors

“…Points directly adjacent to the capillary walls were in excellent agreement with previous reports for P25 TiO 2 ( Figure 4A), showing large signals at 143, 398, 517, and 640 cm −1 attributed to the E g , B 1g , A 1g /B 2g , and E g stretches of the anatase phase, with a small signal present at 197 cm −1 , attributed to the rutile phase, as expected for P25 TiO 2 . [23] Other more subtle features can be seen at higher Raman shifts, which are in good agreement with previous spectra on Co ZIF-67, [24] again showing the proximity of these two layers. The purple layer of the MOFC was also probed ( Figure 4A), and aside from features already attributed to titania, showed excellent agreement with previously published spectra for bulk Co ZIF-67 ( Figure S9, Supporting Information).…”

Energy Transfer‐Induced Photoelectrochemical Improvement from Porous Zeolitic Imidazolate Framework‐Decorated BiVO4 Photoelectrodes

“…[ 48 ] An only difference was the extra peak around 1617 cm –1 in case of BiVO 4 ‐ZIF‐67 sample, which is probably related to ZIF‐67. [ 49 ] A significant change observed in case of bare BiVO 4 is that the symmetric VO stretching mode peak at ≈826 cm –1 shifted to a larger wavenumber after stability measurements. In addition, the symmetric VO bending mode at ≈326 cm –1 shifted to a lower wavenumber after stability measurements.…”

New Members of the Editorial Board and International Advisory Board

“…He was made Professor of Inorganic Chemistry and Catalysis at Utrecht University in 2000, and was appointed Distinguished Professor of the Faculty of Science in 2012. Weckhuysen's research program involves the synthesis, characterization, and application of solid catalysts for the conversion of fossil (crude oil and natural gas) and renewable (biomass) feedstocks into fuels, chemicals, and materials, as well as the development of in situ and operando techniques for studying catalytic solids . Weckhuysen was Co‐Chair of the Editorial Board of ChemCatChem from 2009–2016 and is currently on its International Advisory Board, and he is also on the Editorial Advisory Board of ChemPhysChem .…”