Fabrication of mesoporous SiO2/Au/Co3O4 hollow spheres catalysts with core-shell structure for liquid phase oxidation of benzyl alcohol to benzaldehyde

Electrochemical sensor using cobalt oxide-modified porous carbon for uric acid determination

An electrochemical sensor for the detection of uric acid was constructed using cobalt oxide-modified porous carbon@multi-walled carbon nanotube (MWCNTs) composite material for the modification of the electrode. Firstly, ZIF-67 is generated on carbon nanotubes using the surfactant cetylammonium bromide (CTAB) as template. The vesicles generated by CTAB act as nucleation sites for the in situ growth of ZIF-67. Then, cobalt oxide-modified porous carbon was obtained after high-temperature carbonization of ZIF-67, leading to the formation of cobalt oxide-modified porous carbon@MWCNT composite materials. Co-N and Co-O active sites on the composite material can improve the oxidation of uric acid on the electrode surface, leading to enhanced sensitivity and selectivity for uric acid detection. The sensor has a good linear range from 1 to 40 μM for uric acid detection with a detection limit of 0.09 μM. The sensor was utilized for determination of uric acid in actual serum samples.

Synthesis of a Novel Spherical-Shell-Structure Polymerized Ionic Liquid Microsphere PILM/Au/Al(OH)3 Catalyst for Benzyl Alcohol Oxidation

In order to selectively oxidize benzyl alcohol, a novel noble metal catalyst based on polymer ionic liquids with a core-shell structure was created. First, polymer ionic liquid microspheres (PILMs) were prepared by free radical polymerization. Second, the in situ adsorption of Au nanoparticles on the surface of PILMs was accomplished, thanks to the strong electrostatic interaction between N atoms and metal ions on the diazole ring of PILMs. Additionally, the introduction of Al(OH)₃ prevented the aggregation of Au nanoparticles and promoted the catalytic reaction. Finally, the PILM/Au/Al(OH)₃ catalyst with a core-shell structure was formed. The effectiveness of the PILM/Au/Al(OH)₃ catalyst was assessed by varying the catalyst's type, quantity, amount of Au, amount of H₂O₂, temperature, and reaction time. After five cycles of experiments, the catalyst was effective and reusable. In addition, the potential catalytic mechanism of the catalyst in the oxidation of benzyl alcohol was proposed.

One-Step Construction of a Hollow Au@Bimetal-Organic Framework Core-Shell Catalytic Nanoreactor for Selective Alcohol Oxidation Reaction

Hollow core-shell catalytic nanoreactors have received tremendous attention due to their high mass transfer in catalysis applications. Herein, we present a novel type of well-arranged, hollow core-shell nanoreactors featured with a bimetallic porous Zn/Ni-MOF-2 shell and a tiny Au nanoparticle core. The well-designed hollow Au@Zn/Ni-MOF-2 nanoreactors were constructed through the strategy of a facile one step from a rare crystal-structure transformation without any additional template. These nanoreactors exhibit outstanding multifunctional catalysis for a broad range of alcohol oxidation under the green oxidant environment. Moreover, such hollow nanoreactors show excellent recyclability toward the selective alcohol oxidation. These findings might provide a promising platform for a general construct of various metal-organic framework-based hollow core-shell nanostructures and further highly augmented catalytic applications.