Zhenfeng Zhu

Characterization and activity of mesoporous titanium dioxide beads with high surface areas and controllable pore sizes.

Mesoporous titanium dioxide beads with high surface areas (over 90 m(2)/g) and tunable pore sizes (from 12.8 to 16.5 nm) were synthesized via a solvothermal process heating by microwave irradiation, with ammonia being used as both a source of nitrogen and a control agent for the mesoporous structure. Structural characterization indicated that the mesoporous TiO(2) beads were composed of nanocrystals and pores and the beads possess a optical band gap energy of 3.11 eV. The doping nitrogen was in the form of NH(x) or NO(x) species and was adsorbed on surface of the beads, which caused changes to the surface electronic structure. The results show that the samples which possess higher-order structure, large surface area and well-defined crystallinity have the best performance in photocatalytic activities exhibited as evaluated in the degradation of methylene blue.

Multilayered Mo-Doped TiO2 Nanofibers and Enhanced Photocatalytic Activity

One-dimensional nanostructures of multilayered Mo-doped TiO2 nanofibers with mesoporous structures are successfully synthesize form a hydrothermal process. Mo ions were incorporated into the crystal lattice of anatase TiO2 nanofibers, resulting in a noticeable red shift of the absorption edge and a significant enhancement of visible light absorption. There was different optimum Mo doping content for Mo-doped nanofibers to present the best visible and ultraviolet (UV) photocatalytic activity. The effect of the doping Mo as trapping centers on photocatalysis was investigated in detail and used to explain the difference between the photocatalysis under the illumination of visible and UV light.

Enhanced Photocatalytic Activity of Polyvinylpyrrolidone Assisted Microwave Hydrothermal Grown Tin Oxide Photocatalysts

Enhanced Photocatalytic Activity of Polyvinylpyrrolidone Assisted Microwave Hydrothermal Grown Tin Oxide Photocatalysts nPure and well mono-dispersed SnO2 nanoparticles were synthesized by a microwave assisted hydrothermal method, where polyvinylpyrrolidone (PVP) was used as a surfactant and SnCl2.2H2O, as tin source. The structure and surface morphology of as-obtained products were well characterized by X-ray diffraction, scanning electron microscope and UV-Vis diffuse reflectance spectroscopy. The results show that the particle size of SnO2 nanoparticles is about 200-300 nm and there are many small prisms grown on SnO2 nanoparticles surface.