Well-defined platelet-like hydrazine-cadmium tellurite hybrid microcrystals have been synthesized by a solvothermal reaction of cadmium chloride,sodium tellurite,and hydrazine hydrate in a mixed solvent containing n-propylamine and deionized water.The formula of the hybrid platelet-like microcrystals has been proposed based on a combination of powder X-ray diffraction pattern(PXRD),elemental analysis,thermogravimetic analysis(TGA),and X-ray photoelectron spectroscopy(XPS).Controlled thermal decomposition of this hybrid precursor can lead to the formation of porous platelet-like microarchitectures.Pure porous cadmium telluride architectures were obtained by using hydrochloric acid to dissolve CdTeO3 remaining in the sample after thermal decomposition at 450°C.In addition,unique nanoporous tellurium architectures were obtained by using hydrochloric acid to dissolve the amorphous Cd(N2H4)TeO3 formed after thermal decomposition at 300°C,followed by an in situ topotactic reaction between the residual three-dimensional(3-D)skeleton of cadmium telluride nanocrystallites and−23TeO.Brunauer-Emmett-Teller(BET)analysis and a study of the optical properties of these porous cadmium telluride and tellurium materials have also been carried out.
Polymer-controlled mineralization in aqueous solution or in a mixed solvent media, as well as its com-bination with the interface of air-water can lead to the formation of minerals with unique structures and morphologies, which sheds light on the possibility to mimic the detailed structures of the natural min-erals.
One-dimensional magnetic Ni Co alloy microwires with different microstructures and differently shaped building blocks including spherical particles,multilayer stacked alloy plates,and alloy flowers,have been synthesized by an external magnetic field-assisted solvothermal reaction of mixtures of cobalt(II)chloride and nickel(II)chloride in 1,2-propanediol with different NaOH concentrations.By adjusting the experimental parameters,such as precursor concentration and Ni/Co ratio,Ni Co alloy chains with uniform diameters in the range 500 nm to 1.3μm and lengths ranging from several micrometers to hundreds of micrometers can be obtained.A mechanism of formation of the one-dimensional assemblies of magnetic NiCo microparticles in a weak external magnetic fi eld is proposed.
Well-dispersed M@TiO_(2)(M=Ag,Pd,Au,Pt)nanocomposite particles with a diameter of 200-400 nm can be synthesized on a large scale by a clean photochemical route which does not require any additives using spherical rutile nanoparticles as a support.The sizes of Pt,Au,and Pd nanoparticles formed on the surface of TiO_(2) particles are about 1 nm,5 nm,and 5 nm,respectively,and the diameter of Ag nanoparticles is in the range 2-20 nm.Moreover,the noble metal nanoparticles have good dispersity on the particles of the TiO_(2) support,resulting in excellent catalytic activities.Complete conversion in catalytic CO oxidation is reached at temperatures as low as 333 and 363 K,respectively,for Pt@TiO_(2) and Pd@TiO_(2) catalysts.In addition,the antibacterial effects of the as-synthesized TiO_(2) nanoparticles,silver nanoparticles,and Au@TiO_(2) and Ag@TiO_(2) nanocomposites have been tested against Gram-negative Escherichia coli(E.coli)bacteria.The results demonstrate that the presence of the TiO_(2) matrix enhances the antibacterial effect of silver nanoparticles,and the growth of E.coli can be completely inhibited even if the concentration of Ag in Ag@TiO_(2) nanocomposite is very low(10μg/mL).
Uniform hollow Au@TiO2 core shell spheres with moveable Au nanoparticles were synthesized based on templating against Au@carbon spheres.The diameter of the shell of the Au@TiO2 spheres could be controlled by adjusting the Ti(OC4H9)4 hydrolyzing reaction time or the ratio of Ti(OC4H9)4 to Au@carbon spheres,and the shell thickness of the core-shell spheres can be varied from 25 nm to 40 nm.As prepared hollow Au@TiO2 core-shell spheres display enhanced photocatalytic activity in the initial stage of photocatalytic degradation of methylene blue compared with pure hollow TiO2 spheres and the commercial photocatalyst TiO2(P-25).
