Papers by Author: Yan Li

Abstract: Porous CeO₂ nanostructures were synthesized by a simple template method using cotton fibers as biomaterial template. The phase structure and morphology of the product were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM). The UV-blocking property was evaluated by UV-Vis spectrophotometry. Experimental results showed that the as-synthesized CeO₂ was in a cubic fluorite structure and presented fiber-like structure. The fiber-like CeO₂ nanostructures completely recorded the original morphology of cotton fibers, which consisted of large amounts of coalescent CeO₂ nanoparticles with average particle size in the range of 6-10 nm. The UV test result showed that the UV transmittance of the product was closer to zero in the wavelength below 350 nm, indicating that the product exhibited excellent UV-blocking property.

Abstract: In this paper, we reported that firewood-like CeO₂ nanostructures were synthesized via hydrothermal method in the present of cetyltrimethylammonium bromide (CTAB) for the first time. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were used to characterize the as-obtained sample. The UV absorption property of the product was investigated by UV-vis spectrophotometry. XRD result shows that the product was a cubic fluorite-type CeO₂ phase with good crystallinity. FE-SEM and TEM analysis indicate that the firewood-like CeO₂ nanostructures were composed of CeO₂ nanoparticles with the average size of about 6-10 nm. The CeO₂ shows excellent UV absorption for that the transmittance (T %) of the sample in the UV region almost equal to zero.

Abstract: Porous ZnO microtubes have been synthesized via a facile hydrothermal method based on nanoparticle splicing growth and the preferential etching strategy in the hydrothermal reaction system with high supersaturation. The ZnO tubes have hexangular wurtzite structure with a dimension of about 6 to 12 m in length, 4 m in diameter and about 40 nm in wall thickness, which is made of numerous mesopores with diameter ranging from 40 nm to 200 nm.

Abstract: A novel missile-like ZnO structure has been synthesized solvo-thermally in absolute alcohol using Zn(NO₃)₂·6H₂O and NaOH as starting materials, and characterized by Scanning Electron Microscopy, powder X-ray diffraction and room temperature photoluminescence. The missile-like ZnO crystal, with a wurtzite structure and a blue-green emission at 459 nm, is made up of two symmetrical rocket-like crystals possessing a prismatic base and a hexagonal pyramid linking with each other along plane (0001(_)).

Abstract: ZnO is an important functional semiconductor in application of photoelectric devices. ZnO nano-tubes and the CuO-doped ZnO have been successfully fabricated via hydrothermal method and a solution routine. The samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transformation infrared spectroscopy and room temperature photoluminescence measurement. The results show that the lattice space (d-value) of the CuO-doped ZnO increases while introducing CuO into its structure. Due to the interaction between Cu2+ and the surface atoms of ZnO, a photoluminescence confinement were observed in the CuO-doped ZnO compared with that of nano ZnO.