Tingxian Tao

Synthesis of amine-functionalized Fe3O4@C nanoparticles for lipase immobilization

Amine-functionalized Fe3O4@C nanoparticles have been successfully synthesized on a large scale via a solvothermal route. The morphology, structure and properties of the Fe3O4@C nanoparticles were investigated through different analytical tools. Due to the magnetic nature and the presence of amine-functionalized groups, the as-prepared Fe3O4@C nanoparticles were employed as magnetic carriers for lipase immobilization. Our results indicate that the lipase loading amount on the magnetic Fe3O4@C nanoparticles was about 115.6 mg of protein per g. The factors related to the catalytic activity of the immobilized lipase on the magnetic carriers were systematically investigated. Hydrolytic activity tests reveal that the immobilized lipase retains about 93% of the free enzyme activity. It should be mentioned that the thermal stability of the immobilized lipase was strikingly higher than that of the free lipase. Most importantly, the immobilized lipase retained more than 68% of its initial activities after 10 times reuse. It is hoped that the amine-functionalized Fe3O4@C nanoparticles may find an application in biotechnology and catalysis.

PEG1000-Based Dicationic Acidic Ionic Liquid as an Efficient Catalyst for Mannich-Type Reaction in Water

Abstract PEG1000-based dicationic acidic ionic liquid (PEG1000-DAIL) was found to be an efficient and recyclable catalyst for Mannich-type reaction of different ketones with various aromatic aldehydes and aromatic amines in water to give various β-arylamino ketones in good yields. The catalytic system could be easily recovered and reused for at least six runs only with slight decrease in its activity. GRAPHICAL ABSTRACT

Synthesis, characterisation and photocatalytic properties of BiOCl/amidoxime fibre composites

BiOCl/amidoxime fibre composite photocatalysts have been successfully prepared via ions chelating on fibre. The structure and composition of the product were characterised by XRD, EDS, SEM, FT–IR, XPS and TG. The results indicated that BiOCl was successfully immobilised on the modified commercial fibres. Photocatalytic testing showed that the BiOCl/amidoxime fibre composite exhibited an excellent recycling performance owing to the coordination interactions between BiOCl and amidoxime fibre.

Template-free synthesis and magnetic properties of hollow Cu/Fe3O4 heterodimer sub-microcactus

Hollow Cu/Fe3O4 heterodimer sub-microcactus has been successfully fabricated by a facile one-pot solvothermal method without any templates, which was confirmed by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS) and a magnetic property measurement system. Batch experiments showed that the morphology is strongly influenced by the content of Cu in the Cu/Fe3O4 samples. A mechanism for the formation of the hollow heterodimer sub-microcactus by a cooperation of oriented attachment and localized Ostwald ripening processes has been proposed based on the observations of time-dependent experiments. Magnetic measurements illustrated that the prepared hollow heterodimer sub-microcactus are superparamagnetic magnets with a saturation magnetization of 65.2 emu g−1. The synthesized hollow Cu/Fe3O4 heterodimer sub-microcactus may have important applications in catalysis, energy storage and biomedical applications.

Highly efficient synthesis of arylnaphthalenes by modified fibre–palladium(II) complex catalysed Suzuki reaction in air

The modified fibre–palladium(II) complex was a highly efficient, recoverable and heterogeneous catalyst giving high yields in the synthesis of arylnaphthalenes by a Suzuki reaction in air. The heterogeneous catalyst can be readily recovered by simple filtration and reused at least six times without significant reduction in its activity.

Suzuki cross-coupling of aryl halides with phenylboronic acid catalysed by an amidoxime fibres-nickel(0) complex

Amidoxime fibres–nickel(0) complexes [Ni(0)–AOFs] were synthesised by combining a Ni2+-solution with amidoxime fibres and reduced by NaH2PO2. The Ni(0)–AOFs are inexpensive phosphine-free recyclable heterogeneous catalysts for the Suzuki coupling reaction of aryl halides with phenylboronic acid to provide the corresponding biphenyls in high yields. The heterogeneous catalyst can be readily recovered by simple filtration and reused several times without significant loss of activity.