This study focuses on the challenge of converting ZnO films into uniform zeolitic imidazolate framework-8 (ZIF-8) layers or membranes, an essential key step in shaping metal-organic frameworks (MOFs). It compares two ZnO deposition techniques: atomic layer deposition (ALD) and physical vapor deposition (PVD), examining how each method affects the surface chemistry of ZnO and its subsequent conversion into ZIF-8. The investigation includes contact angle measurements using methanol and water to assess surface wettability as well as X-ray diffraction (XRD) analysis combined with electronic microscopy to characterize the resulting ZIF-8 layers. The study indicates that ALD ZnO films are more hydrophilic, with a water contact angle of ∼75°, compared to the more hydrophobic PVD films, which exhibit a contact angle of ∼98°. XRD analysis reveals that PVD films display a pronounced (002) crystal orientation, while ALD films consist of randomly oriented nanocrystals. To optimize the conversion of ZnO to ZIF-8, the methanol-to-water ratio was adjusted, with a 3:1 mixture yielding the most uniform ZIF-8 layers. Additionally, thermal treatment of PVD films at 600 °C significantly altered their surface reactivity and conversion behavior, leading to distinct ZIF-8 morphologies. In contrast, ALD films exhibited a higher conversion efficiency, producing continuous, well-crystallized ZIF-8 layers with minimal defects. This improved performance is attributed to their superior surface wettability and reactivity. These findings underscore the critical role of ZnO surface chemistry in ZIF-8 formation and emphasize the importance of optimizing both deposition methods and conversion conditions to achieve high-quality MOF layers.
- Wettability-driven control of ZnO-to-ZIF-8 conversion: the role of surface chemistry in growing continuous metal–organic framework layers
- Kevin Dedecker - Université de Montpellier, IEM - Institut Européen des MembranesThierry Thami - Université de Montpellier, IEM - Institut Européen des MembranesMartin Drobek - Université de Montpellier, IEM - Institut Européen des MembranesMikhael Bechelany - Université de Montpellier, IEM - Institut Européen des MembranesAntoine Barnabé - Centre National de la Recherche ScientifiqueLionel Presmanes - Centre National de la Recherche ScientifiqueAnne Julbe - Université de Montpellier, IEM - Institut Européen des Membranes
- Langmuir, Vol.42(19), pp.13947-13960
- LAAS–CNRS Micro and Nanotechnologies Platform
- 99259563909311
- IEM - Institut Européen des Membranes
- English
- Journal article
- hal-05665417