Search

Abstract: The Raman spectra for SrBi4−x La x Ti4O15 (x=0.00–1.00) ceramic samples are investigated to explore the influence of doping on the structure of SrBi4Ti4O15. Lanthanum-doping results in the shifts of the Raman modes involved in the vibration of the cations at A site of the pseudo-pervoskite slabs, Bi3+ ions in the Bi2O2 layers, and the stretching mode of TiO6 octahedra. The shifts of these modes indicate that La3+ ions prefer the A site of SrBi4Ti4O15 as x≤0.10, and as x>0.10, they are incorporated into Bi2O2 layers. [Copyright &y& Elsevier]

Nanocrystalline SnO2 powders of about 3 nm in size have been prepared by a microwave irradiation heating technique from an aqueous solution in the presence of SnCl4 and urea. The nanocrystalline SnO2 particles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), differential scanning calorimetric (DSC), thermogravimetric analysis (TG), and reflection spectrum. A bandgap is estimated to be 4.5 eV from the optical measurement of the nanoparticles. [Copyright &y& Elsevier]

Abstract: The diameter-controllable SnO2 porous structures were fabricated by templating against the polystyrene nanospheres. The porous SnO2 nanostructures present efficient photocatalytic performance in degradation of MO under violet light, which has rarely been reported in the past. The photocatalytic ability can be enhanced through decreasing the porous diameter. Spectral examinations and analyses reveal that the porous structures and the existing oxygen vacancies are responsible for the appearing photocatalytic ability. Such porous structure is also expected to present good performance in gas sensing and electrochemical properties. [Copyright &y& Elsevier]

Abstract: PbS and Bi2S3 nanocrystals with well-controlled sizes and shapes were easily produced from molecular precursors (xanthate) in ethylene diamine (en) solution at room temperature. When lead or bismuth ethylxanthate were added into en solution, the precipitates were instantly formed, and subsequently, PbS cubes and flower-like Bi2S3 hierarchical structures were obtained if the mixtures were left still for 5days under ambient conditions. This work not only provides a facile route to synthesize chalcogenides with well-defined nano- and microstructures in a solution-phase system, but also gives insight into understanding on decomposition behavior of molecular precursors in various solvents. [Copyright &y& Elsevier]

Abstract: A photochemical reaction route was developed to synthesize bismuth selenide (Bi2Se3) nanoparticles and nanorods. In an aqueous solution, bismuth nitrate (Bi(NO3)3) reacted with sodium selenosufate in the presence of reducing agent and complexing agent, and the dispersed Bi2Se3 nanoparticles were obtained with the average size of 35 nm. The nanorods were prepared via an alumina template route in the same solution. We carried out experiments to study the formation mechanism in the morphology control of the products and found that series of factors played an effective role including the irradiation time, pH value, the reducing agents and the species of complexing agents. The products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). [Copyright &y& Elsevier]