Hexagonal Cages and Lewis Acid-Base Sites in a Metal-Organic Framework for Synergistic CO Capture and Conversion under Mild Conditions.

The cycloaddition reaction of carbon dioxide (CO) is a highly economic solution to becoming carbon-neutral. Herein, we have designed and synthesized a robust zinc(II)-organic framework (Zn-Ade-TCPE) by a function-directed strategy. Zn-Ade-TCPE possesses uncommon hexagonal cages with Lewis acid-base bifunctional sites and displays a high adsorption capacity for CO.

[TiZrO(COO)] Cluster: An Ideal Inorganic Building Unit for Photoactive Metal-Organic Frameworks.

Metal-organic frameworks (MOFs) based on Ti-oxo clusters (Ti-MOFs) represent a naturally self-assembled superlattice of TiO nanoparticles separated by designable organic linkers as antenna chromophores, epitomizing a promising platform for solar energy conversion. However, despite the vast, diverse, and well-developed Ti-cluster chemistry, only a scarce number of Ti-MOFs have been documented. The synthetic conditions of most Ti-based clusters are incompatible with those required for MOF crystallization, which has severely limited the development of Ti-MOFs.

Seed-Mediated Synthesis of Metal-Organic Frameworks.

The synthesis of phase-pure metal-organic frameworks (MOFs) is of prime importance but remains a significant challenge because of the flexible and diversified coordination modes between metal ions and organic linkers. In this work, we report the synthesis of phase-pure MOFs via a facile seed-mediated approach. For several "accompanying" pairs of Zr-porphyrinic MOFs that are prone to yield mixtures, by fixing all reaction parameters except introducing seed crystals, MOFs in phase-pure forms have been obtained because the stage of MOF nucleation, which generates mixed nuclei, is bypassed.

Visible-Light Photoreduction of CO2 in a Metal-Organic Framework: Boosting Electron-Hole Separation via Electron Trap States.

It is highly desirable to convert CO2 to valuable fuels or chemicals by means of solar energy, which requires CO2 enrichment around photocatalysts from the atmosphere. Here we demonstrate that a porphyrin-involved metal-organic framework (MOF), PCN-222, can selectively capture and further photoreduce CO2 with high efficiency under visible-light irradiation. Mechanistic information gleaned from ultrafast transient absorption spectroscopy (combined with time-resolved photoluminescence spectroscopy) has elucidated the relationship between the photocatalytic activity and the electron-hole separation efficiency.