Yongqian Lei

Synthesis, characterization and assembly of BiOCl nanostructure and their photocatalytic properties

In this article, a two-dimensional (2D) nanoplate and a 3D hierarchical structure of BiOCl were synthesized through a simple sonochemical route. Compared with previous preparation methods, the 2D nanoplates can be prepared at a relatively short time (about 30 min) with low energy used. Additionally, these 2D nanoplates can easily assemble into a 3D hierarchical structure with the surfactant reagents. The obtained products were well crystallized and subsequently characterized by a range of methods, such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission microscopy (HRTEM), selected area electron diffraction (SAED) and Raman spectroscopy. A possible mechanical growth route was also proposed based on the experiments. The photocatalytic properties of the prepared samples were further investigated by photocatalytic decomposition of Methene Orange (MO) dye, which indicated that the 3D hierarchical structure can effectively improve photocatalytic activity.

Hierarchically structured Fe3O4 microspheres: morphology control and their application in wastewater treatment

Novel three-dimensional (3D) flower-like Fe3O4 microspheres were synthesized by a facile precursor-templated conversion method. The precursor was prepared by an ultrasound-assisted hydrothermal method without the help of any surfactant. The possible formation mechanism of the precursor was proposed, and it was found that the synthetic parameters for the precursor such as the time of ultrasonic pretreatment and NH4Ac concentration are crucial for the formation of the flower-like hierarchical precursor structure. The flower-like Fe3O4 microspheres obtained by calcining the precursor in N2 exhibit superparamagnetic behaviour and show relative high saturation magnetization at room temperature. Furthermore, the as-obtained product, with high BET surface area, has been used as an absorbent in wastewater treatment and exhibit a strong capability to remove organic pollutants.

Synthesis and optical properties of europium-complex-doped inorganic/organic hybrid materials built from oxo-hydroxo organotin nano building blocks.

Hybrid materials doped with novel europium complexes were synthesized using PMMA-co-Sn(12)Clusters (copolymers from oxohydroxo-organotin dimethacrylate and methylmethacrylate) as the matrix material. Two types of hybrid materials were obtained: the physically doped product, PMMA-co-Sn(12)Cluster/Eu(TTA)(3)phen, and the grafted product, PMMA-co-Sn(12)Cluster-co-[EuAA(TTA)(2)phen] (TTA = 2-thenoyltrifluoroacetone, phen = phenanthroline and AA = acrylic acid). The hybrid materials exhibited characteristic luminescence of the Eu(3+) ions, and also showed relative especial optical properties compared with samples just using PMMA as the matrix material. The PMMA-co-Sn(12)Cluster matrix exhibited a high physical doping quantity of [Eu(TTA)(3)phen], which can be attributed to the special structure of this kind of hybrid material. GPC (gel-permeation chromatography), TGA (thermogravimetric analysis), SEM, (1)H NMR, ICP (inductively coupled plasma), (119)Sn NMR, FTIR, and diffuse reflectance techniques were employed to characterize the structures and properties of these hybrid materials.

One-pot synthesis of flowerlike Ni7S6 and its application in selective hydrogenation of chloronitrobenzene

Uniform flowerlike Ni7S6 nanostructures composed of nanopetals with sharp tips have been synthesized by a mild hydrothermal method. On the basis of a series of contrast experiments, a probable growth mechanism and fabrication process of the flowerlike products was proposed. The catalytic performances of the as-synthesized samples were tested in selective hydrogenation of chloronitrobezene. Compared with other nickel sulfide samples with different morphologies and structures, flowerlike Ni7S6 samples show much higher activity and selectivity in the hydrogenations of nitrobenzene and chloronitrobenzenes with different chlorine substituent site. To the best of our knowledge, this is the first time that uniform flower-like Ni7S6 with high selectivity to nitro group have been synthesized in solution.

Porous Co3O4 microcubes: hydrothermal synthesis, catalytic and magnetic properties

Well-defined porous Co3O4 microcubes have been synthesized by a simple one-pot solvothermal method combined with subsequent calcination. The formation mechanism of the cube-like precursor was proposed based on the anisotropic intrinsic structure of CoCO3. Importantly, after thermal treatment, the cube-like morphology could be completely preserved. Moreover, the thermal decomposition of the corresponding precursor led to the formation of porous structure. The effects of calcination temperature on the catalytic properties of Co3O4 samples were investigated and the results demonstrated that 600 °C was superior among three samples with the highest catalytic properties. Additionally, as an antiferromagnetic material, the sample showed a certain degree of ferromagnetism under the external magnetic field.

Direct hydrothermal synthesis of single-crystalline triangular Fe3O4 nanoprisms

Single-crystalline Fe3O4 triangular nanoprisms (TNPs) were fabricated by a facile hydrothermal route in the presence of 1,3-propanediamine (PDA). It was found that the EG to PDA volume ratio played an important role in the formation of the TNP structures and greatly affected the morphology of the magnetites.

Near-infrared luminescent copolymerized hybrid materials built from tin nanoclusters and PMMA

Novel near-infrared (NIR) luminescent copolymerized hybrid materials were prepared by covalently grafting and physically doping Ln complexes (Ln = Er, Sm, Yb, and Nd) into a copolymer matrix built from nanobuilding blocks. The structures of the obtained hybrid materials were investigated by Fourier transform infrared (FTIR) spectra, nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), and thermogravimetric analysis (TGA). In the photoluminescence studies, the hybrid materials showed characteristic NIR luminescence of corresponding Ln(3+) ions through intramolecular energy transfer from ligands to Ln(3+) ions. Transparent films of these materials can be easily prepared through spin-coating on indium tin oxide (ITO) glasses taking advantage of the matrix nature.

Hydrothermal synthesis and upconversion photoluminescence properties of lanthanide doped YF3 sub-microflowers

Yttrium fluoride sub-microflowers were synthesized by facile hydrothermal route without using any expensive or environmental unfriendly agents. The influences of various hydrothermal parameters on the final products were investigated. It was found that the concentration of NH3·H2O had a significant effect on the morphology change of YF3 sub-microcrystals. The growth mechanism of the as-obtained YF3 sub-microflowers was proposed. The multicolor upconversion (UC) photoluminescence (PL) was successfully realized in Yb3+/Tm3+, Yb3+/Ho3+ and Yb3+/Er3+ doped YF3 sub-microflowers when excited by 980 nm laser diode (LD). The pumping power dependence of the fluorescent intensity is investigated to understand the fundamental UC mechanism.

Cobalt and nickel with various morphologies: mineralizer-assisted synthesis, formation mechanism, and magnetic properties

Uniform Ni microflowers and Co microspheres have been synthesized by a simple one-pot hydrothermal method with high yield. The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and superconducting quantum interference device (SQUID). The synthesis of various shaped nanomaterials was achieved using different alkali metal salts. This is the first report on synthesizing Ni and Co nanostructures using different mineralization to modulate the morphology of the final products. In addition, these synthesized Ni and Co nanocrystals exhibit room-temperature enhanced magnetic properties. Such a facile one-pot approach may also be applied for the synthesis of other metal materials.

CuIn(WO4)(2) nanospindles and nanorods: controlled synthesis and host for lanthanide near-infrared luminescence properties

CuIn(WO4)2 porous nanospindles and nanorods were synthesized through a low-cost hydrothermal method without introducing any template or surfactants. An interesting formation mechanism, namely “oriented attachment”, was observed for the growth of nanorods based on the experimental process and the anisotropic intrinsic crystalline structure of CuIn(WO4)2, which is uncommon in such a system. The near-infrared luminescence of lanthanide ions (Er, Nd, Yb and Ho) doped CuIn(WO4)2nanostructures, especially in the 1300–1600 nm region, was discussed and of particular interest for telecommunications applications. X-Ray diffraction, scanning electron microscopy, transmission electron microscopy, electron diffraction and photoluminescence spectra were used to characterize these materials.