Mesoporous Metal–Organic Frameworks: Synthetic Strategies and Emerging Applications

Abstract

Metal-organic frameworks (MOFs) have attracted much attention over the past two decades due to their highly promising applications not only in the fields of gas storage, separation, catalysis, drug delivery, and sensors, but also in relatively new fields such as electric, magnetic, and optical materials resulting from their extremely high surface areas, open channels and large pore cavities compared with traditional porous materials like carbon and inorganic zeolites. Particularly, MOFs involving pores within the mesoscopic scale possess unique textural properties, leading to a series of research in the design and applications of mesoporous MOFs. Unlike previous Reviews, apart from focusing on recent advances in the synthetic routes, unique characteristics and applications of mesoporous MOFs, this Review also mentions the derivatives, composites, and hierarchical MOF-based systems that contain mesoporosity, and technical boundaries and challenges brought by the drawbacks of mesoporosity. Moreover, this Review subsequently reveals promising perspectives of how recently discovered approaches to different morphologies of MOFs (not necessarily entirely mesoporous) and their corresponding performances can be extended to minimize the shortcomings of mesoporosity, thus providing a wider and brighter scope of future research into mesoporous MOFs, but not just limited to the finite progress in the target substances alone.

Emerging Delivery Strategies of Carbon Monoxide for Therapeutic Applications: from CO Gas to CO Releasing Nanomaterials

“…Taking advantage of high porosity and large specific surface area, porous nanomaterials and macromolecular scaffolds (such as mesoporous silica nanoparticles (MSNs), metal organic frameworks (MOFs), polymeric micelles, and dendrimers) have attracted considerable attention to load a significant amount of CORMs and improve clinical response simultaneously. For example, Carmona et al have successfully encapsulated cationic Mn‐based photoactive ALF472 + and cisplatin (anticancer drug) into the cavities of the anionic matrix of mesoporous silica Al‐MCM‐41 nanoparticles, producing two light‐responsive hybrid CO releasing nanomaterials, named ALF472@Al‐MCM‐41 and ALF472‐cisplatin@Al‐MCM‐41.…”

From Zeolitic Imidazolate Framework‐8 to Metal‐Organic Frameworks (MOFs): Representative Substance for the General Study of Pioneering MOF Applications

“…The initially microporous structure of ZIF‐8 provides high‐density active sites for various catalysis. The exceptionally tunable framework of ZIF‐8 also enables people to adjust its porosity to a mesoporous or hierarchical degree in many ways, which makes it possible that ZIF‐8 can cooperate in catalytic processes with many other functional materials. Typically, the integration of metal particles inside m SiO 2 @ZIF‐8 ( m SiO 2 = mesoporous silica) can result in spherical monodispersed metal‐ m SiO 2 @ZIF‐8 core‐shell composite as extraordinary nanocatalysts .…”

Functional Macro‐Microporous Metal–Organic Frameworks for Improving the Catalytic Performance

“…To solve such challenges, extensive research endeavors have been devoted to creating hierarchical-pore structures in MOFs (H-MOFs) to reduce the impact of molecular diffusion. [11][12][13] Designing ligands is one of the methods for the preparation of H-MOFs. [14,15] Recently, Cai and Jiang controllably created different pore structures in UiO-66 [11] by introducing excess and versatile monocarboxylic acid as organic ligand to preoccupy the coordination sites.…”

“…Soft template method is another emerging strategy for the preparation of H-MOFs. [13,16] Tan and Zeng used surfactant to selfassemble into micell, which served as a soft template for MOFs growth and was subsequently removed to generate hierarchical pores. [17] As far as we know, two kinds of surfactants were often used for such method, i.e., cetyltrimethylammonium bromide and polyvinylpyrrolidone (PVP).…”