Metal-organic framework (MOF) nanoparticles, also called porous coordination polymers, are a major part of nanomaterials science, and their role in catalysis is becoming central. The extraordinary variability and richness of their structures afford engineering synergies between the metal nodes, functional linkers, encapsulated substrates, or nanoparticles for multiple and selective heterogeneous interactions and activations in these MOF-based nanocatalysts. Pyrolysis of MOF-nanoparticle composites forms highly porous N- or P-doped graphitized MOF-derived nanomaterials that are increasingly used as efficient catalysts especially in electro- and photocatalysis. This review first briefly summarizes this background of MOF nanoparticle catalysis and then comprehensively reviews the fast-growing literature reported during the last years. The major parts are catalysis of organic and molecular reactions, electrocatalysis, photocatalysis, and views of prospects. Major challenges of our society are addressed using these well-defined heterogeneous catalysts in the fields of synthesis, energy, and environment. In spite of the many achievements, enormous progress is still necessary to improve our understanding of the processes involved beyond the proof-of-concept, particularly for selective methane oxidation, hydrogen production, water splitting, CO2 reduction to methanol, nitrogen fixation, and water depollution.

State of the Art and Prospects in Metal-Organic Framework (MOF)-Based and MOF-Derived Nanocatalysis.

More than 95% (in volume) of all of today’s chemical products are manufactured through catalytic processes, making research into more efficient catalytic materials a thrilling and very dynamic rese...

Metal–Organic Frameworks in Heterogeneous Catalysis: Recent Progress, New Trends, and Future Perspectives

Metal–organic frameworks: Structures and functional applications

A surfactant-stabilized coordination strategy is used to make two-dimensional (2D) single-atom catalysts (SACs) with an ultrahigh Pt loading of 12.0 wt %, by assembly of pre-formed single Pt atom coordinated porphyrin precursors into free-standing metal-organic framework (MOF) nanosheets with an ultrathin thickness of 2.4±0.9 nm. This is the first example of 2D MOF-based SACs. Remarkably, the 2D SACs exhibit a record-high photocatalytic H2 evolution rate of 11 320 μmol g-1  h-1 via water splitting under visible light irradiation (λ>420 nm) compared with those of reported MOF-based photocatalysts. Moreover, the MOF nanosheets can be readily drop-casted onto solid substrates, forming thin films while still retaining their photocatalytic activity, which is highly desirable for practical solar H2 production.

Ultrathin Metal-Organic Framework Nanosheets with Ultrahigh Loading of Single Pt Atoms for Efficient Visible-Light-Driven Photocatalytic H 2 Evolution

Semiconductor photocatalysis, a sustainable and renewable technology, is deemed to be a new path to resolve environmental pollution and energy shortage. The development of effective photocatalysts, especially the metal-free photocatalysts, is a critical determinant of this technique. The recently emerged 2D material of black phosphorus with distinctive properties of tunable direct bandgap, ultrahigh charge mobility, fortified optical absorption, large specific surface area, and anisotropic structure has captured enormous attention since the first exfoliation of bulk black phosphorus into mono- or few layered phosphorene in 2014. In this article, the state-of-the-art preparation methods are first summarized for bulk black phosphorus, phosphorene, and black phosphorus quantum dot and then the fundamental structure and electronic and optical properties are analyzed to evaluate its feasibility as a metal-free photocatalyst. Various modifications on black phosphorus are also summarized to enhance its photocatalytic performance. Furthermore, the multifarious applications such as solar to energy conversion, organic removal, disinfection, nitrogen fixation, and photodynamic therapy are discussed and some of the future challenges and opportunities for black phosphorus research are proposed. This review reveals that the rising star of black phosphorus will be a multifunctional material in the postgraphene era.

Black Phosphorus, a Rising Star 2D Nanomaterial in the Post-Graphene Era: Synthesis, Properties, Modifications, and Photocatalysis Applications

Recently, the emergence of photoactive metal-organic frameworks (MOFs) has given great prospects for their applications as photocatalytic materials in visible-light-driven hydrogen evolution. Herein, a highly photoactive visible-light-driven material for H2 evolution was prepared by introducing methylthio terephthalate into a MOF lattice via solvent-assisted ligand-exchange method. Accordingly, a first methylthio-functionalized porous MOF decorated with Pt co-catalyst for efficient photocatalytic H2 evolution was achieved, which exhibited a high quantum yield (8.90 %) at 420 nm by use sacrificial triethanolamine. This hybrid material exhibited perfect H2 production rate as high as 3814.0 μmol g-1  h-1 , which even is one order of magnitude higher than that of the state-of-the-art Pt/MOF photocatalyst derived from aminoterephthalate.

https://biblio.ugent.be/publication/8727187/file/8727202.pdf

A Methylthio-Functionalized-MOF Photocatalyst with High Performance for Visible-Light-Driven H2 Evolution.

The rational design of organic semiconductors based on crystalline covalent organic frameworks (COFs) as efficient photocatalysts is highly desirable. In this study, the first example of phenanthroimidazole-based COFs is reported: PImCOF1 with an imine linkage and PIm-COF2 with a β-ketoenamine-linkage. Both COF materials showed substantial optical properties. The average hydrogen evolution rate was 7417.5 μmolg-1h-1 for PIm-COF2, which was 20 times higher than that of PIm-COF1 (358.5 μmolg-1h-1). This can be attributed to the strong donor-acceptor effect of PIm-COF2 and the continuous separation and transfer of the photoexcited electron-hole pair from the phenanthro[9,10-d]imidazole moiety.

/pdf/phenanthroimidazole-based-covalent-organic-frameworks-with-1m3e6pxv.pdf

Dong-Lai Pan

Papers

A Methylthio-Functionalized-MOF Photocatalyst with High Performance for Visible-Light-Driven H2 Evolution.

Phenanthroimidazole-based Covalent Organic Frameworks with Enhanced Activity for the Photocatalytic Hydrogen Evolution Reaction