The Ultra-Fast Room-Temperature Electrosynthesis of Zeolitic Imidazolate Framework Films

Efficient and scalable fabrication of metal-organic frameworks (MOFs) as thin films is a key step toward their commercial applications. However, it remains challenging to process most MOFs into films due to their chemical and physical properties. Here, we report a cation coordination-regulated strategy for the rapid and continuous electrochemical synthesis of high-quality zeolitic imidazolate framework (ZIF) films with a tunable thickness. Through controlled experiments and computational investigations, we find that the more important role of modulators (e.g., ammonia) in the fast nucleation of ZIFs is to lower the energy barrier for the coordination of metal ions with ligands by forming intermediates rather than the widely acknowledged deprotonation effect of weak bases. Using this kinetically accelerating strategy, the ultrafast (within 10 s) deposition of well-intergrown ZIF-8 films with a high deposition efficiency is achieved from aqueous electrolytes at room temperature. Moreover, by combining our strategy with metal plating techniques, ZIF-8 films were anodically deposited on various substrates, including copper foils and porous anodic aluminum oxide (AAO) membranes. This strategy is universal for the deposition of a diverse range of ZIFs (such as ZIF-67, ZIF-4, and ZIF-7) and enables roll-to-roll fabrication of ZIF films under mild conditions.