Recent Progress on Core-Shell Zeolitic Imidazole Frameworks: A Review of Synthesis and Applications

Zeolitic Imidazole Frameworks (ZIFs) have recently appeared as a new class of nonporous materials featuring notable physicochemical properties. In particular, ZIFs with core-shell structures have drawn a great deal of attention from research communities owing to their unique features, including superior specific surface area, high porosity content, extraordinary thermal, chemical, and structural stability, feasible synthesis conditions in a mild reaction, and facile growth on external surfaces of core nanostructures. This growth facilitates the synthesis of core/shell hybrid materials, which contain both organic (2-MIM) and inorganic (metal nodes) groups. As a structural advantage, the core/shell configuration favorably promotes the potential implementation of ZIFs in various functional fields, e.g. catalysis, drug delivery, adsorption, separation, and purification applications. The current review investigates recent advances in synthesizing and applying ZIFs with core-shell structures. This research review is divided into four parts. The first part overviews synthesis methods for ZIFs and discusses these nanostructures' structural and material characteristics. The second part summarizes recent achievements and findings on synthesizing different types of ZIFs featuring core-shell structures. In the third part, potential applications of these novel nanostructured materials are presented, and their features are summarized in the final part.