Hierarchical FeWO4 microcrystals: solvothermal synthesis and their photocatalytic and magnetic properties.

Highly hierarchical platelike FeWO(4) microcrystals have been synthesized by a simple solvothermal route using FeCl(3) x 6 H(2)O and Na(2)WO(4) x 2 H(2)O as precursors, where ethylene glycol (EG) plays an important role as a capping agent in directing growth and self-assembly of such unique structures. In addition, a certain amount of CH(3)COONa (NaAc) was necessary for the formation of such unique FeWO(4) microstructures. The photocatalytic property of as-synthesized hierarchical FeWO(4) microcrystals has been first studied, which shows excellent photocatalytic activity for the degradation of rhodamine B (RhB) under UV and visible light irradiation (modeling sunlight). Moreover, magnetic measurement indicates that hexangular FeWO(4) platelike microcrystals show a small ferromagnetic ordering at low temperature because of spin-canting of antiferromagnetic materials and surface spins of FeWO(4) nanoparticles.

Controllable synthesis of VSB-5 microspheres and microrods: growth mechanism and selective hydrogenation catalysis.

Nanoporous VSB-5 nickel phosphate molecular sieves with relatively well controllable sizes and morphology of microspheres assembled from nanorods were synthesized at 140 degrees C over a short time in the presence of hexamethylenetetramine (HMT) by a facile hydrothermal method. The pH value, reaction time, and ratio of HMT to NaHPO2.H2O crucially influence the morphology and quality of the final products. By adjusting the pH value of the initial reaction solution, the morphology changes from disperse rods to microspheres assembled from rods and finally to a large quantity of fibers, and the diameters of the VSB-5 rods can be varied. The catalytic activity of VSB-5 in selective hydrogenation of several unsaturated organic compounds was tested. Nickel(II) in VSB-5 can selectively catalyze hydrogenation of C=C in trans-cinnamaldehyde and 3-methylcrotonaldehyde. In addition, since nitrobenzene (NB) and 2-chloronitrobenzene could be reduced to aniline (AN) and 2-chloroaniline with high selectivity, VSB-5 could have potential applications in synthesizing dyes, agrochemicals, and pharmaceuticals.

High-quality luminescent tellurium nanowires of several nanometers in diameter and high aspect ratio synthesized by a poly (vinyl pyrrolidone)-assisted hydrothermal process.

Large-scale selective synthesis of uniform single crystalline tellurium nanowires with a diameter of 4-9 nm, and microbelts with a width of 250-800 nm and tens of micrometers in length, can be realized by a poly (vinyl pyrrolidone) (PVP)-assisted hydrothermal process. The formation of tellurium nanowires and nanobelts in the presence of PVP is strongly dependent on the reaction conditions such as temperature, the amount of PVP, and reaction time. The results demonstrated that the keys for selective synthesis of Te nanobelts and nanowires are to modulate the growth rates of (100), (101), and (110) planes in the presence of PVP and to precisely control the reaction kinetics. High-quality luminescent ultrathin t-Te nanowires with a diameter of 4-9 nm display strong luminescent emission in the blue-violet region. This approach provides a facile route for the production of high-quality tellurium nanostructures with an interesting optical property. Furthermore, the synthesized ultrathin nanowires with deep blue color and nanobelts in gray color by this approach can be well dispersed in water or ethanol, making it possible for further engineering of their surfaces to prepare other hybrid core-shell nanostructures.

Large scale synthesis of uniform silver@carbon rich composite (carbon and cross-linked PVA) sub-microcables by a facile green chemistry carbonization approach.

A facile green chemistry carbonization method has been discovered for the synthesis of uniform silver@carbon rich composite (carbon and cross-linked polyvinyl alcohol) core-shell sub-microcables in large quantities, where the carbon sources such as glucose-based saccharides have played important roles in the formation of these novel sub-microcables.

Large-scale synthesis of flexible gold/cross-linked-PVA sub-microcables and cross-linked-PVA tubes/fibers by using templating approaches based on silver/cross-linked-PVA sub-microcables.

Well-defined silver/cross-linked-poly(vinyl alcohol) (PVA) sub-microcables, which were synthesized from a hydrothermal reaction using AgCl and PVA as precursors, have been used as sacrificial templates to fabricate gold/cross-linked-PVA sub-microcables by etching the silver/cross-linked-PVA sub-microcables with tetrachloroaurate(III). In addition, well-defined cross-linked-PVA sub-microtubes/sub-microfibers can also be produced by the removal of the silver cores of such sub-microcables at ambient temperature. The channel diameter and the shell thickness could be tuned by controlling the diameter of the core sub-microfibers and the shell thickness of the precursor sub-microcables. These cross-linked-PVA-based cables, tubes, and fibers have the potential to be used in future applications such as nanodevices.