Post-modification of robust guanine-quadruplex-linked 2,2'-pyridine-containing HOF-25 with Ni(ClO) 4 ·6H 2 O followed by exfoliation using sonication method affords hydrogen-bonded organic framework (HOF) nanosheets (NSs) of HOF-25-Ni in the yeild of 56%. TEM and AFM technologies disclose the ultrathin nature of HOF-25-Ni NSs with thickness of 4.4 nm. STM observation determines the presence of sql segments assembled from HOF-25-Ni building blocks at the heptanoic acid/highly oriented pyrolytic graphite interface, supporting the simulated 2D supramolecular framework. ICP analysis, XAS, and XPS spectra prove the successful immobilization of atomic nickel sites on the 20% total 2,2'-pyridine moieties in crystalline HOF-25-Ni. With the aid of [Ru(bpy) 3 ] 2+ and triisopropanolamine, 10 wt% HOF-25-Ni NSs dispersed on graphene oxide efficiently promotes visible light-driven CO 2 reduction, showing a 96.3% CO selectivity with a prominent conversion rate up to 24323 μmol g -1 h -1 .

Hydrogen-Bonded Organic Framework Ultrathin Nanosheets for Efficient Visible Light Photocatalytic CO2 Reduction.

Photocatalytic water splitting and carbon dioxide (CO2) reduction provide promising solutions to global energy and environmental issues. In recent years, metal-organic frameworks (MOFs), a class of crystalline porous solids featuring well-defined and tailorable structures as well as high surface areas, have captured great interest toward photocatalytic water splitting and CO2 reduction. In this review, the semiconductor-like behavior of MOFs is first discussed. We then summarize the recent advances in photocatalytic water splitting and CO2 reduction over MOF-based materials and focus on the unique advantage of MOFs for clarifying the structure-property relationship in photocatalysis. In addition, some representative characterization techniques have been presented to unveil the photocatalytic kinetics and reaction intermediates in MOF-based systems. Finally, the challenges, and perspectives for future directions are proposed.

Metal-Organic Frameworks for Photocatalytic Water Splitting and CO2 Reduction.

Here we report a facile direct solid-state reaction strategy employing crystalline MoS2 coupled conductive black titania (BT) to create nanocomposites with BT−MoS2 substantial synergy. BT-MoS2 shows a typical surface Vo-rich...

Crystalline MoS2 enhanced conductive black titania for efficient solar to chemical conversions: photocatalytic CO2 reduction and CH4 oxidation

Multicomponent reactions (MCRs) combine at least three reactants to afford the desired product in a highly atom-economic way and are therefore viewed as efficient one-pot combinatorial synthesis tools allowing one to significantly boost molecular complexity and diversity. Nowadays, MCRs are no longer confined to organic synthesis and have found applications in materials chemistry. In particular, MCRs can be used to prepare covalent organic frameworks (COFs), which are crystalline porous materials assembled from organic monomers and exhibit a broad range of properties and applications. This synthetic approach retains the advantages of small-molecule MCRs, not only strengthening the skeletal robustness of COFs, but also providing additional driving forces for their crystallization, and has been used to prepare a series of robust COFs with diverse applications. The present perspective article provides the general background for MCRs, discusses the types of MCRs employed for COF synthesis to date, and addresses the related critical challenges and future perspectives to inspire the MCR-based design of new robust COFs and promote further progress in this emerging field.

Construction of Covalent Organic Frameworks via Multicomponent Reactions.

Targeted H2O activation to manipulate the selective photocatalytic reduction of CO2 to CH3OH over carbon nitride supported cobalt sulfide

Direct photo-oxidation of methane to methanol over a mono-iron hydroxyl site

Biomimetic active sites on monolayered metal–organic frameworks for artificial photosynthesis

Herein, we report the synthesis of a metal-organic layer, Hf-Ru-Au, containing Ru(bipyridine)32+-type photosensitizers and (phosphine)-AuCl catalysts for photoredox Au-catalyzed cross-coupling of allenoates, alkenes, or alkynes with aryldiazonium salts to afford furanone, tetrahydrofuran, or aryl alkyne derivatives, respectively. Site isolation of (phosphine)-AuCl complexes in Hf-Ru-Au prevents Au catalyst deactivation via ligand redistribution, Au(I) disproportionation, and aryl-phosphine reductive elimination, while the proximity between the Ru photosensitizers and Au catalysts enhances catalytic efficiency, with 14-200 times higher activity over those of the homogeneous controls in the cross-coupling reactions.

Site Isolation in Metal-Organic Layers Enhances Photoredox Gold Catalysis.

Covalent organic frameworks (COFs) have received broad interest owing to their permanent porosity, high stability, and tunable functionalities. COFs with long-range π-conjugation and photosensitizing building blocks have been explored for sustainable photocatalysis. Herein, we report the first example of COF-based energy transfer Ni catalysis. A pyrene-based COF with sp2 carbon-conjugation was synthesized and used to coordinate Ni(II) centers through bipyridine moieties. Under light irradiation, enhanced energy transfer in the COF facilitated the excitation of Ni centers to catalyze borylation and trifluoromethylation reactions of aryl halides. The COF showed two orders of magnitude higher efficiency in these reactions than its homogeneous control and could be recovered and reused without significant loss of catalytic activity.

Enhanced Energy Transfer in A π-Conjugated Covalent Organic Framework Facilitates Excited-State Nickel Catalysis.

In a recent issue of Journal of the American Chemical Society , Dong and co-workers described a chiral covalent-organic framework assembled from porphyrin photosensitizers, chiral propargylamine linkers, and ammonium bromide phase-transfer groups for enantioselective photooxidation of sulfides to sulfoxides, including photocatalytic synthesis of ( R )-modafinil for treating excessive sleepiness. In a recent issue of Journal of the American Chemical Society , Dong and co-workers described a chiral covalent-organic framework assembled from porphyrin photosensitizers, chiral propargylamine linkers, and ammonium bromide phase-transfer groups for enantioselective photooxidation of sulfides to sulfoxides, including photocatalytic synthesis of ( R )-modafinil for treating excessive sleepiness. 

Wenbin Lin

Papers

Direct photo-oxidation of methane to methanol over a mono-iron hydroxyl site

Biomimetic active sites on monolayered metal–organic frameworks for artificial photosynthesis

Site Isolation in Metal-Organic Layers Enhances Photoredox Gold Catalysis.

Enhanced Energy Transfer in A π-Conjugated Covalent Organic Framework Facilitates Excited-State Nickel Catalysis.

A chiral covalent-organic framework for asymmetric photooxidation in water