Low Temperature Growth of One-Dimensional Al and Al2O3 Nano/Micro-Structures Using Al and SnO2 Powder Mixture

One-dimensional Al and Al2O3 nano/microstructures were fabricated via thermal oxidation of Al and SnO2 powder mixtures at temperatures below the melting point of Al (660 oC). Furthermore, the synthesis process was carried out in air at atmospheric pressure, which made the process very simple and easy. Sn metal particles with spherical shape were observed on the tips of the Al and Al2O3 nano/microstructures, suggesting that the nano/microstructures were grown via a catalyst-assisted growth mechanism. The Sn acted as a catalyst for growing the Al and Al2O3 nano/microstructures. The Sn with low melting point (232 oC) was produced via the reduction of SnO2 by Al, and formed catalyst droplets at the growth temperatures. Al atoms diffused and dissolved into the Sn liquid droplets, leading to the nucleation and then the growth of the Al and Al2O3 nano/microstructures. At 400 oC, the diffusion of Al atoms into the Sn liquid droplets was associated with high stress generated at the Al2O3/Al interface. At 600 oC close to the melting point of Al, Al atoms were diffused from the thin Al liquid layer, which was formed on the surface of the Al powder, to the Sn liquid droplets. Simultaneously, the Al atoms reacted with oxygen in air and formed solid Al2O3 nuclei. A relatively strong ultraviolet emission band centered at 330 nm was observed in the sample prepared at 600 oC.

Optical and structural properties of Nd doped SnO2 powder fabricated by the sol–gel method

UV excitation of Nd doped SnO2 leads to visible & NIR emission: Nd3+ ions are optically active in SnO2 nanoparticles.

Influence of the Ratio of ZnO/SnO2 on the Photocatalytic Property of ZnO/SnO2 Nanometer Powder

ZnO/SnO2 nanocomposite powder were prepared by coprecipitation method with SnCl4·5H2O, ZnNO3·6H2O, HCl, NaOH as raw materials. Influence of different mol ratio of ZnO/SnO2 on the photocatalytic activity of ZnO/SnO2 nanocomposite powder was researched by the degradation of methyl orange as a reaction model. The particle size and dispersion of ZnO/SnO2 powder was characterized by transmission electron microscope(TEM). The results show that the photocatalytic activity of ZnO/SnO2 nanocomposite powder was increased significantly when compounded by SnO2, the photoactivating activity of ZnO/SnO2 powder starts increasing and then decreasing when the ratio of ZnO/SnO2 decreases. When ZnO:SnO2 is the ratio of 4:1(mol ratio)，the photocatalytic activity of ZnO/SnO2 nanocomposite powder is the best and the degradation rate of methyl orange is 42.09% when visible light illuminate for 225 minutes, particle size is 20-30 nanometer and dispersion is good.