A new three-dimensional copper dithiocarbamate-copper iodide coordination polymer [Cu(Me2dtc)2(CuI)3]n (Me2dtc=N,N-dimethyldithiocarbamate) was synthesized by reactions of Cu(OAc)2,NaI and Na(Me2dtc) in DMF solution,characterized by elemental analysis,IR spectrum,and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system,space group C2/c with a=1.293 89(17) nm,b=1.077 61(11) nm,c=1.456 05(17) nm,β=115.585 (4)°,V=1.831 1 (4) nm3,Z=4,Dc=3.175 g·cm-3,Mr=875.28,λ (Mo Kα)=0.071 073 nm,μ=10.082 mm-1,F(000)=1 604,the final R=0.029 5 and wR=0.081 7. A total of 2 083 unique reflections were collected,of which 1 918 with I>2σ(I) were observed. The Cu atoms are Cu(Ⅰ)/Cu(Ⅱ) mixed-valence and they have two different coordinate geometries,namely planar square and tetrahedron. This three-dimensional structure consists of individual Cu(Me2dtc)2 molecules linking together CuI polymeric chains which run parallel to the [001] direction vis Cu-S bonds.
The size of the gold particles is a very important parameter to get active catalysts.This paper reports a novel colloidal deposition method to prepare Au/LaVO_(4)nanocomposite catalyst with monodispersed Au colloids and uniform LaVO_(4)nanoplates in nonpolar solvent.Monodispersed Au colloids with tunable size(such as 2,5,7,11,13,and 16 nm)and LaVO_(4)nanocrystals with well-defi ned shapes were pre-synthesized assisted with oleic acid/amine.During the following immobilization process,the particle size and shape of Au and LaVO_(4)were nearly preserved.As-prepared Au/LaVO_(4)nanocomposite showed high catalytic activity for CO oxidation at room temperature.Since sizes of gold particles were well-defi ned before the immobilization process,size effect of gold particles was easy to be investigated and the results show that 5-nm Au/LaVO_(4)nanocomposite has the highest activity for CO oxidation.This synthetic method can be extended further for the preparation of other composite nanomaterials.
Junfeng LiuWei ChenXiangwen LiuKebin ZhouYadong Li
Uniform rice-like CdS particles were synthesized in cyclohexane/Triton X-100/n-pentanol/water quaternary microemulsions. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, and electron diffraction. The results indicate that the size and the shape of the rice-like CdS particles can be influenced by the molar ratio of water to the surfactant(w value) and the reactant concentrations.
A novel type of cadmium orthosilicate nanowire was prepared successfully based on a hydrothermal synthetic process in a mixed water-ethanol solvent system. The composition, morphology, and microscope structure were studied by XRD and HRTEM. From the HRTEM images, these nanowires were found to be composed of Cd2SiO3 nanoparticles, which can be called "nanocluster wires". This kind of nanocluster wire will have potential applications and attract increasing interest because it behaves as quantum dots.
MgO nanobelts were successfully synthesized via a co-precipitation synthetic way by employing ammonia and salvolatile as co-precipitator. TEM characterization showed that these nanobelts were composed of uniform hexagonal shaped MgO nanocrystals. The formation of this new-type nanostructures was attributed to the crystal structures of the MgCO3·3H2O precursor. TG was adopted to show the gradual conversion process of from MgCO3·3H2O to MgO. Due to the large surface areas and the largely exposed (100) surfaces, these nanobelts may find their applications in catalysis fields.
