Jinbiao Shi

Solvent Impedes CO2 Cycloaddition on Metal-Organic Frameworks

The catalytic performance of metal-organic frameworks (MOFs) for the synthesis of cyclic carbonate from carbon dioxide and epoxides has been explored under solvent and solvent-free conditions, respectively. It was found that MOF catalysts have significantly improved catalytic activities in solvent-free CO2 cycloaddition reactions than those in solvent. The mechanism was discussed with regard to the competition of solvent with substrate to adhere MOF catalysts during the reaction process.

Ultrathin and Porous Carbon Nanosheet Supporting Bimetallic Nanoparticles for High Performance Electrocatalysis

Developing hybrid carbon materials with unique micro/nanostructured and multicomponent features is of great importance in catalysis, energy storage, and energy conversion. Herein, we demonstrate the formation of a novel kind of hybrid carbon material, that is, bimetallic nanoparticles supported by ultrathin (≈5.5u2005nm) and porous carbon nanosheets, by the pyrolysis of preformed bimetallic metal–organic framework nanosheets. This hybrid carbon nanostructure combines the advantages of highly exposed nanoparticles that are readily accessible to the reactant, multiple active sites such as metal–metal and metal–nitrogen sites and ultrathin carbon layers, and highly efficient electron transport. Owing to these unique features, the bimetallic carbon nanosheets exhibit excellent electrocatalytic performance for the oxygen reduction reaction.

Carbon dioxide droplets stabilized by g-C3N4

Here we propose the emulsification of CO2 and water with graphitic carbon nitride (g-C3N4), in which the g-C3N4-stabilized CO2 droplets were utilized as “microreactors” for in situ photocatalytic CO2 reduction. The g-C3N4 sheets assembling at the CO2/water interface can serve both as an emulsifier and photocatalyst, which can greatly promote the conversion of CO2 to formic acid.

Room-Temperature Synthesis of Covalent Organic Framework (COF-LZU1) Nanobars in CO2/Water Solvent

The development of facile, rapid, low-energy, environmentally benign routes for the synthesis of covalent organic frameworks (COFs) is of great interest. This study concerns the utilization of water containing dissolved CO2 as a solvent for the room-temperature synthesis of COF. The as-synthesized particles, denoted COF-LZU1, combine advantages of good crystallinity, nanoscale size, and high surface area, which suggests promising application as a support for heterogeneous catalysts. Moreover, this versatile CO2 -assisted method is also applicable for the room-temperature synthesis of Cu-COF-LZU1. This method gives rise to new opportunities for fabricating COFs and COF-based materials with different compositions and structures.

Tin(IV) Sulfide Greatly Improves the Catalytic Performance of UiO-66 for Carbon Dioxide Cycloaddition

To overcome the limitations of metal–organic frameworks (MOFs) for catalysis (e.g., low catalytic activities resulting from blockage of the active metal centers by organic linkers) is of great importance. Herein, we demonstrate the formation of UiO‐66 nanoparticles with ultrasmall size and linker defects with the aid of SnS2 nanosheets. The UiO‐66 nanoparticles supported by SnS2 nanosheets were found to exhibit excellent catalytic activity for the cycloaddition reaction of CO2 with propylene oxide under solvent‐free and co‐catalyst‐free conditions. Outstandingly, the catalytic activity was 11u2005times higher than that of the pure UiO‐66 catalyst under optimum conditions. We thus provide a promising route to modify MOF particles thus to promote their catalytic performance.

Photocatalytic CO2 Transformation to CH4 by Ag/Pd Bimetals Supported on N-Doped TiO2 Nanosheet

To develop photocatalysts with desirable compositions and structures for improving the efficiency and selectivity of CO2 conversion to CH4 under mild conditions is of great importance. Here, we design an effective photocatalyst of bimetal (Ag/Pd) nanoalloys supported on nitrogen-doped TiO2 nanosheet for CO2 conversion. Such a novel photocatalyst combines multiple advantages of abundant Ti3+ ions, oxygen vacancies, and substitutional nitrogen that are favorable for catalyzing CO2 reduction. It was found that CO2 could be efficiently transformed to CH4 under mild conditions, i.e., in aqueous solution and at atmospheric pressure and room temperature. The maximum production rate of CH4 can reach 79.0 μmol g-1 h-1. Moreover, the Ag/Pd bimetals supported on N-doped TiO2 nanosheet exhibit high selectivity to CH4. The as-synthesized photocatalyst can be well recycled for CO2 reduction.

MIL-125-NH2@TiO2 Core–Shell Particles Produced by a Post-Solvothermal Route for High-Performance Photocatalytic H2 Production

Metal-organic frameworks (MOFs) have proven to be an interesting class of sacrificial precursors of functional inorganic materials for catalysis, energy storage, and conversion applications. However, the controlled synthesis of MOF-derived materials with desirable compositions, structures, and properties still remains a big challenge. Herein, we propose a post-solvothermal route for the outer-to-inner loss of organic linkers from MOF, which is simple, rapid, and controllable and can be operated at temperature much lower than that of the commonly adopted pyrolysis method. By such a strategy, the MIL-125-NH2 particles coated by TiO2 nanosheets were produced, and the thickness of TiO2 shell can be easily tuned. The MIL-125-NH2@TiO2 core-shell particles combine the advantages of highly active TiO2 nanosheets, MIL-125-NH2 photosensitizer, plenty of linker defects and oxygen vacancies, and mesoporous structure, which allows them to be utilized as photocatalysts for the visible-light-driven hydrogen production reaction. It is remarkable that the hydrogen evolution rate by MIL-125-NH2@TiO2 can be enhanced 70 times compared with the pristine MIL-125-NH2. Such a route can be easily applied to the synthesis of different kinds of MOF-derived functional materials.

Metal–Organic Framework-Stabilized CO2/Water Interfacial Route for Photocatalytic CO2 Conversion

Here, we propose a CO2/water interfacial route for photocatalytic CO2 conversion by utilizing a metal-organic framework (MOF) as both an emulsifier and a catalyst. The CO2 reduction occurring at the CO2/water interface produces formate with remarkably enhanced efficiency as compared with that in conventional solvent. The route is efficient, facile, adjustable, and environmentally benign, which is applicable for the CO2 transformation photocatalyzed by different kinds of MOFs.