Diamonds are forever: A diamond‐like framework in which the C–C bonds are replaced with rigid phenyl rings (see picture) is not only structurally stable but also has a large internal surface area. This porous aromatic framework (PAF‐1) demonstrates high uptake capacities of hydrogen and carbon dioxide as well as benzene and toluene vapors, and has an unprecedented surface area of 7100 m2 g−1.

Metal-organic framework (MOF) materials, which are constructed from metal ions or metal ion clusters and bridging organic linkers, exhibit regular crystalline lattices with relatively well-defined pore structures and interesting properties. As a new class of porous solid materials, MOFs are attractive for a variety of industrial applications including separation membranes - a rapidly developing research area. Many reports have discussed the synthesis and applications of MOFs and MOF thin films, but relatively few have addressed MOF membranes. This critical review provides an overview of the diverse MOF membranes that have been prepared, beginning with a brief introduction to the current techniques for the fabrication of MOF membranes. Gas and liquid separation applications with different MOF membranes are also included (175 references).

Porous organic materials have garnered colossal interest with the scientific fraternity due to their excellent gas sorption performances, catalytic abilities, energy storage capacities, and other intriguing applications. This review encompasses the recent significant breakthroughs and the conventional functions and practices in the field of porous organic materials to find useful applications and imparts a comprehensive understanding of the strategic evolution of the design and synthetic approaches of porous organic materials with tunable characteristics. We present an exhaustive analysis of the design strategies with special emphasis on the topologies of crystalline and amorphous porous organic materials. In addition to elucidating the structure-function correlation and state-of-the-art applications of porous organic materials, we address the challenges and restrictions that prevent us from realizing porous organic materials with tailored structures and properties for useful applications.

Three-dimensional porous crystalline polyimide covalent organic frameworks (termed PI-COFs) have been synthesized. These PI-COFs feature non- or interpenetrated structures that can be obtained by choosing tetrahedral building units of different sizes. Both PI-COFs show high thermal stability (>450 °C) and surface area (up to 2403 m(2) g(-1)). They also show high loading and good release control for drug delivery applications.

Covalent organic frameworks (COFs) are an emerging class of porous crystalline polymers with a wide variety of applications. They are currently synthesized through only a few chemical reactions, limiting the access and exploitation of new structures and properties. Here we report that the imidization reaction can be used to prepare a series of polyimide (PI) COFs with pore size as large as 42 × 53 Å(2), which is among the largest reported to date, and surface area as high as 2,346 m(2) g(-1), which exceeds that of all amorphous porous PIs and is among the highest reported for two-dimensional COFs. These PI COFs are thermally stable up to 530 °C. We also assemble a large dye molecule into a COF that shows sensitive temperature-dependent luminescent properties.

Hydrogen production through electrochemical process is at the heart of key renewable energy technologies including water splitting and hydrogen fuel cells. Despite tremendous efforts, exploring cheap, efficient and durable electrocatalysts for hydrogen evolution still remains as a great challenge. Here we synthesize a nickel–carbon-based catalyst, from carbonization of metal-organic frameworks, to replace currently best-known platinum-based materials for electrocatalytic hydrogen evolution. This nickel-carbon-based catalyst can be activated to obtain isolated nickel atoms on the graphitic carbon support when applying electrochemical potential, exhibiting highly efficient hydrogen evolution performance with high exchange current density of 1.2 mA cm−2 and impressive durability. This work may enable new opportunities for designing and tuning properties of electrocatalysts at atomic scale for large-scale water electrolysis.

We summarize in this review the current state-of-the-art development of three dimensional covalent organic frameworks.

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