Yabin Huang

Template synthesis and characterization of WO3/TiO2 composite nanotubes

Highly ordered WO3/TiO2 composite nanotubes have been successfully prepared by the combination of the sol?gel chemical method and the anodic aluminium oxide (AAO) templating method. The diameter of the WO3/TiO2 composite nanotubes is about 100?nm, which is in good agreement with the pore diameter of the AAO template. The composite nanotubes are composed of mixed oxides of W6+ and Ti4+.

Direct observation of photoinduced charge redistribution of WO3–TiO2 double layer nanocomposite films by photoassisted Kelvin force microscopy

The microscopic photoinduced charge redistribution between heterogeneous semiconductor nanofilms of WO3 and TiO2 double layers (written as WO3–TiO2 nanocomposite films) was directly observed using Kelvin probe force microscopy (KFM) coupled with an UV light source. Under illumination the surface potential morphologies of WO3–TiO2 nanocomposite films changed from 162to592mV, which was associated with the photoinduced charge transfer between WO3 and TiO2 nanoparticles due to the energy level alignment between them. This improved technique of photoassisted KFM was presented to visualize the photoinduced charge transfer between different semiconductor nanoparticles on microscopic scale.

A study of poly (N-vinylcarbazole) adsorbed on silver surface by SERS

Abstract Surface-enhanced Raman scattering (SERS) spectrum of poly ( N -vinylcarbazole) (PVC) adsorbed on silver surface and the adsorbent structure of PVC have been studied for the first time. The results and discussion show that PVC molecules are strongly adsorbed on the silver surface through benzene ring and hetero-five-membered ring and are possibly oxidized by the silver active surface.

A STUDY ON THE LANGMUIR–BLODGETT (LB) FILMS OF C60/POLY (N-VINYLCARBAZOLE) (PVK) POLYMERS

The Langmuir–Blodgett (LB) films of Poly (N-vinylcarbazole) (PVK) Polymers and its hybrid films with arachidic acid (AA) and C60 were prepared by a vertical deposition method. Atomic Force Microscopy (AFM) and UV-Vis absorption spectroscopy were used to investigate the assembly of PVK/AA and PVK/C60/AA LB films. It was found that the C60 molecules could be aggregated into smaller particles on the base of PVK polymers. The photoluminescence (PL) of PVK was dramatically quenched resulting from the electron transfer from PVK to C60 in their composite films.

The molecular orientation of PNBA on silver nanoparticles

The molecular orientations ofp-nitrobenzoic acid (PNBA) on the surface of silver nanoparticles and silver mirror have been investigated by using surface enhanced Raman scattering (SERS) and UV-visible absorption spectroscopy. In the mixed system of silver colloid/PNBA/ethanol, the orientation of PNBA on silver nanoparticles remarkably different from that on silver mirror was observed, and it mainly resulted from the cooperation effect of the adsorption to surface active sites on silver under the pressure of aqueous molecules. This result is of some significance for further studying surface-interfacial structures and properties of silver nanoparticles, and the technique used in this note is feasible to get the SERS spectra of some molecules insoluble in aqueous solution.

SYNTHESIS AND CHARACTERIZATION OF DIFFERENT MORPHOLOGICAL LITHIUM TITANATE

Lithium titanate powders of different morphologies were synthesized by improved hydrothermal technique, which was performed at 90°C and atmospheric pressure for 20 h. By changing the solution in the reaction, nanoparticles, flowers petal-like structures, and nanorods of lithium titanate have been obtained, especially nanoparticles with well-crystalline structures were obtained. The morphology and micro-structure of the as-synthesized products were characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and selected-area electron diffraction (SAED).

TEMPLATE SYNTHESIS OF ALIGNED SiO2 SUBMICRO-WIRES

Aligned silicon dioxide (SiO2) submicro-wires have been synthesized from tetraethyl orthosilicate (TEOS) by anodic aluminum oxide (AAO) template method. The products were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS) and X-ray diffraction (XRD).