High-efficiency Photocatalytic Oxidation of Benzyl Alcohol by NH2-UiO-66-(Indole-2,3-Dione)-Fe.

The photocatalytic oxidation of biomass-derived benzyl alcohol provides a promising way for the synthesis of benzoic acid, which is an important intermediate with wide applications. To improve the efficiency of photocatalytic benzyl alcohol oxidation to benzoic acid is of great interest. In this work, we propose the utilization of NH2-UiO-66-ID-Fe catalyst for photocatalytic oxidation of benzyl alcohol to benzoic acid, where NH2-UiO-66 is a typically used metal-organic framework, ID is indole-2,3-dione (ID) that has biocompatibility, light absorption property and can be covalently combined with amino-functionalized substances. The NH2-UiO-66-ID-Fe catalyst exhibits improved light absorption and photo-generated electron-hole separation ability compared with NH2-UiO-66. The photocatalytic performance of NH2-UiO-66-ID-Fe was examined for the oxidation of bio-based benzyl alcohol under mild conditions of air atmosphere, room temperature and no additive or additional oxidant involved. The results show that the conversion of benzyl alcohol and the selectivity to benzoic acid could both reach over 99% in 6 h, and the generation rate of benzoic acid per gram of catalyst is 3.36 mmol g-1 h-1. The reaction mechanism was detected by radical trapping method and in situ electron paramagnetic resonance. This study presents an efficient and environmentally benign avenue for the synthesis of carboxylic acid compounds.

Cu/Cu2O nanocrystals for electrocatalytic carbon dioxide reduction to multi-carbon products.

We demonstrate the electrochemical conversion of carbon dioxide into multi-carbon products catalyzed by Cu/Cu2O nanocrystals, with a maximum C2+ faradaic efficiency of 75% in 0.10 M K2SO4 aqueous solution at -2.0 V versus Ag/AgCl and a partial current density of 34 mA cm-2.

SnS2/polypyrrole for high-efficiency photocatalytic oxidation of benzylamine.

Here, SnS2/polypyrrole (PPy) was synthesized, which shows high catalytic activity for the photocatalytic oxidation of benzylamine under mild conditions (at 25 °C, in air and without adding an additional sacrificial reagent, redox mediator and photosensitizer).

Cu3(BTC)2 nanoflakes synthesized in an ionic liquid/water binary solvent and their catalytic properties.

Low-dimensional metal-organic frameworks (MOFs) exhibit enhanced properties compared with three-dimensional (3D) geometry MOFs in many fields. In this work, we demonstrate the synthesis of Cu3(BTC)2 (BTC = benzene-1,3,5-tricarboxylate) nanoflakes in a binary solvent of ionic liquid (IL) and water. Such a MOF architecture has a high surface area and abundant unsaturated coordination metal sites, making them attractive for adsorption and catalysis. For example, in catalyzing the oxidation reactions of a series of alcohols, the Cu3(BTC)2 nanoflakes exhibit a high performance that is superior to Cu3(BTC)2 microparticles synthesized in a conventional solvent. Experimental and theoretical studies reveal that the IL accelerates the crystallization of Cu3(BTC)2, while water plays a role in stripping the Cu3(BTC)2 blocks that are formed at an early stage through its attack on the crystal plane of Cu3(BTC)2. Such an in situ crystallization-exfoliation process that uses an IL/water solvent opens a new route for producing low-dimensional MOFs.

ZIF-9(III) nanosheets synthesized in ionic liquid/ethanol mixture for efficient photocatalytic hydrogen production.

To improve the photocatalytic performance of metal-organic frameworks is of great importance. We synthesized the nanosheets of a zeolitic imidazolate framework (ZIF-9(III)) in ionic liquid/ethanol solution, with an average thickness of 4.6 nm. The as-synthesized ZIF-9(III) nanosheets have optoelectronic properties superior to the three-dimensional ZIF-9(III) synthesized by the conventional solvothermal method. The ZIF-9(III) nanosheets exhibit high activity for photocatalytic hydrogen production under visible light irradiation. The maximum hydrogen production rate can reach 112.37 mmol g-1 h-1, while that by three-dimensional ZIF-9(III) is 29.64 mmol g-1 h-1 under the same experimental conditions.

Periodically nanoporous hydrogen-bonded organic frameworks for high performance photocatalysis.

The development of highly catalytic hydrogen-bonded organic frameworks (HOFs) is of great importance, but remains challenging. Herein, we demonstrate the fabrication of a periodically nanoporous HOF for high performance photocatalysis. Compared with the conventional microporous HOFs, the nanoporous HOF architecture has a larger number of free carboxyl groups on the surface and presents greatly improved photoelectrochemical properties. It exhibits high catalytic activity for the photo-oxidative coupling of amines under mild conditions such as air atmosphere and room temperature and without any co-catalysts, sacrificial reagents or photosensitizers. The relationship between the structure, properties and catalytic performance of the nanoporous HOF was studied by experimental and theoretical investigations. It shows that such a HOF structure facilitates reactant adsorption and O2 dissociation, thus promoting the oxidative coupling reaction. This work provides a new way for improving the catalytic performance of a single HOF.

Co(NO3)2/covalent organic framework nanoparticles for high-efficiency photocatalytic oxidation of thioanisole.

Herein, we demonstrated a highly efficient photocatalytic sulfide oxidation reaction at ambient conditions without a sacrificial reagent or redox mediator, by using Co(NO3)2/covalent organic framework nanoparticles as a photocatalyst.

Anchoring Ionic Liquid in Copper Electrocatalyst for Improving CO2 Conversion to Ethylene.

Electrochemical conversion of CO2 to valuable fuels is appealing for CO2 fixation and energy storage. The Cu-based catalysts feature unique superiorities, but achieving high ethylene selectivity is still restricted. In this study, we propose the anchoring of an ionic liquid (IL) on a Cu electrocatalyst for improving the electrochemical CO2 reduction to ethylene. In a water-based electrolyte and a commonly used H-type cell, a high ethylene Faradaic efficiency of 77.3 % was achieved at -1.49 V (vs. RHE). Experimental and theoretical studies reveal that an IL can modify the electronic structure of a Cu catalyst through its interaction with Cu, making it more conducive to *CO dimerization for ethylene formation.

Highly Electrocatalytic Ethylene Production from CO2 on Nanodefective Cu Nanosheets.

The electrochemical synthesis of chemicals from carbon dioxide, which is an easily available and renewable carbon resource, is of great importance. However, to achieve high product selectivity for desirable C2 products like ethylene is a big challenge. Here we design Cu nanosheets with nanoscaled defects (2-14 nm) for the electrochemical production of ethylene from carbon dioxide. A high ethylene Faradaic efficiency of 83.2% is achieved. It is proved that the nanoscaled defects can enrich the reaction intermediates and hydroxyl ions on the electrocatalyst, thus promoting C-C coupling for ethylene formation.

Improved photocatalytic performance of metal-organic frameworks for CO2 conversion by ligand modification.

Here we demonstrate that the utilization of 2,4,6-tris(4-pyridyl)pyridine (tpy) for metal-organic framework modification can greatly improve the photocatalytic performance for CO2 reduction. The electron-donating nature of tpy enables the charge transfer effect, which induces strong CO2 binding affinity, facilitates *COOH formation and promotes CO2-to-CO conversion.

Manganese acting as a high-performance heterogeneous electrocatalyst in carbon dioxide reduction.

Developing highly efficient electrocatalysts based on cheap and earth-abundant metals for CO2 reduction is of great importance. Here we demonstrate that the electrocatalytic activity of manganese-based heterogeneous catalyst can be significantly improved through halogen and nitrogen dual-coordination to modulate the electronic structure of manganese atom. Such an electrocatalyst for CO2 reduction exhibits a maximum CO faradaic efficiency of 97% and high current density of ~10 mA cm-2 at a low overpotential of 0.49 V. Moreover, the turnover frequency can reach 38347 h-1 at overpotential of 0.49 V, which is the highest among the reported heterogeneous electrocatalysts for CO2 reduction. In situ X-ray absorption experiment and density-functional theory calculation reveal the modified electronic structure of the active manganese site, on which the free energy barrier for intermediate formation is greatly reduced, thus resulting in a great improvement of CO2 reduction performance.

One-step synthesis of ultrathin α-Co(OH)2 nanomeshes and their high electrocatalytic activity toward the oxygen evolution reaction.

Herein, we demonstrate for the first time the one-step synthesis of ultrathin α-Co(OH)2 nanomeshes by an imidazole-directed route. The α-Co(OH)2 nanomeshes combine the advantages of ultrathin thickness (3 nm), small mesopores (3.7 nm), large specific surface area (181.1 m2 g-1) and high surface oxygen vacancy density, which exhibit excellent electrocatalytic performance for the oxygen evolution reaction.