Narrow Results

Bismuth nanowires with width of 10~20 nm, and length of ~200 nm were rapidly prepared from the reduction of Bi(NO₃)₃•5H₂O by ethylene glycol (EG) in alkaline solution under microwave irradiation for 5 minutes. The product was characterized by XRD, TEM and SAED. The effects of the microwave irradiation, the alkaline solution, and the solvent on the formation of bismuth nanowires were also investigated.

The three-dimensional (3D) mesoporous titanium dioxide (TiO₂) was synthesized by microwave-assisted hydrothermal method, using titanium sulfate as titanium source and urea to adjust pH value. Its structure and photocatalytic oxidation properties were studied. The results show that the TiO₂ particles have a 3D mesoporous structure, uniform distribution and spherical shape, the average diameter is about 0.67$\mu$m. These properties provide strong light adsorption, high specific surface area, which increases the active site of the photocatalyst, porosity can also enhance the ability of the material to adsorb pollutants, thus has better stability. It was applied to photocatalytic degradation of 10mg/L rhodamine B (RhB) solution. After 80min of irradiation under 420nm ultraviolet (UV) light, the degradation rate of RhB reached more than 90%. In addition, it also provided an excellent photocatalytic efficiency of removing Hg⁰ in simulated flue gas. The removal efficiency could still reach over 86% after 40 h, which could be used in the treatment of heavy metal pollutants such as metallurgical flue gas.

Cu₂Se nanowires with diameters of about 25 nm and several hundred nm in length were synthesized at room temperature using a Se²⁻ solution prepared by microwave-assisted method. The influencing factors to product morphologies were investigated on the basis of series of control experiments. The as-synthesized products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The optical properties were studied by means of UV-Vis absorption spectroscopy and photoluminescence (PL) spectrum. The results show that the direct band gap energy of the Cu₂Se nanowires is 2.02 eV. Copper sources, molar ratio of Cu/Se element, microwave and reducing agent significantly influence the morphology of the final products. Thus, product morphologies are controllable by simply regulating reaction conditions.