Two-dimensional metal–organic framework nanosheets: synthesis and applications

Abstract

Two-dimensional (2D) metal-organic framework (MOF) nanosheets are attracting increasing research attention due to their unique properties originating from their ultrathin thickness, large surface area and high surface-to-volume atom ratios. Many great advances have been made in the synthesis and application of 2D MOF nanosheets over the past few years. In this review, we summarize the recent advances in the synthesis of 2D MOF nanosheets by using top-down methods, e.g. sonication exfoliation, mechanical exfoliation, Li-intercalation exfoliation and chemical exfoliation, and bottom-up methods, i.e. interfacial synthesis, three-layer synthesis, surfactant-assisted synthesis, modulated synthesis, and sonication synthesis. In addition, the recent progress in 2D MOF nanosheet-based nanocomposites is also briefly introduced. The potential applications of 2D MOF nanosheets in gas separation, energy conversion and storage, catalysis, sensors and biomedicine are discussed. Finally, we give our personal insights into the challenges and opportunities for the future research of 2D MOF nanosheets and their composites.

2D Nanosheets and Their Composite Membranes for Water, Gas, and Ion Separation

“…[20] B) GO/FLG membrane preparation on porous substrate by spraycoating. [24] Because of their highly ordered structure and strong chemical bonds, MOFs are three-dimensional (3D) crystals when prepared without dimensional controls. bridging ligands that usually form crystalline compounds.…”

Structural Engineering of Low‐Dimensional Metal–Organic Frameworks: Synthesis, Properties, and Applications

“…[30][31][32][33][34][35][36][37] Since the discovery of carbon nanotubes (CNTs) in the early 1990s, 1D nanostructures, such as nanowires, nanotubes, and nanorods, have been extensively investigated because of their unique geometrical and electronic characteristics. [48][49][50] These types of MOFs, such as 1D single-walled MOF nanotubes, 1D hexagonal MOF nanorods, ultrathin 2D MOF nanosheets, [51][52][53] have similar morphological features to those of the other 1D or 2D nanomaterials, which endows them with distinctive dimensional-dependent properties including high aspect ratio and abundant accessible active sites. [41][42][43][44][45][46][47] More recently, LD MOFs have attracted intensive interest and been investigated in various applications.…”

“…[48][49][50] These types of MOFs, such as 1D single-walled MOF nanotubes, 1D hexagonal MOF nanorods, ultrathin 2D MOF nanosheets, [51][52][53] have similar morphological features to those of the other 1D or 2D nanomaterials, which endows them with distinctive dimensional-dependent properties including high aspect ratio and abundant accessible active sites. [60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75] Although the advantages and challenges of 1D metal-organic nanotubes [76] and 2D MOF nanosheets [48,50,56] have been well summarized by several previous review articles, the research field of LD MOFs is currently at a stage of rapid development, as indicated by annually increased amount of publications (Figure 2). To achieve effective and controllable preparation of LD MOFs, a large number of synthetic methods have been developed, such as template method, ultrasonic exfoliation, surfactant-assisted growth, three-layer method, etc.…”

A Phthalocyanine‐Based Layered Two‐Dimensional Conjugated Metal–Organic Framework as a Highly Efficient Electrocatalyst for the Oxygen Reduction Reaction

“…[2,13,14] However,w ith this method the welldefined molecular active sites are sacrificed. [13,14,[16][17][18][19][20][21][22][23][24] In particular,s uch MOFs can provide an ideal platform for the investigation of the mechanism of the ORR process,w hich is essential for the rational design of electrocatalysts. [13,14,[16][17][18][19][20][21][22][23][24] In particular,s uch MOFs can provide an ideal platform for the investigation of the mechanism of the ORR process,w hich is essential for the rational design of electrocatalysts.…”