Huajun Yu

Fabrication, characterization and optical properties of TiO2 nanotube arrays on boron-doped diamond film through liquid phase deposition

TiO2 nanotube(TiNT) arrays were deposited on boron-doped diamond films by a liquid-phase deposition method with ZnO nanorod arrays as the template. The different morphologies of TiNTs have been obtained by controlling the morphology of ZnO template. The X-ray diffraction and energy-dispersive X-ray analysis show that the ZnO nanorod arrays template has been removed in the TiNTs formation process. The crystalline quality of the TiNTs is improved by increasing the annealing temperature. The band gap of the TiNTs is about 3.25 eV estimated by the UV-Vis absorption spectroscopy, which is close to the value of bulk TiO2. In the photoluminescence spectrum, a broad visible emission in a range of ca. 550–750 nm appears due to the surface oxygen vacancies and defects.

Preparation and Magnetic Properties of Submicron CrO2 Thin Film on Poly-crystal TiO2 Film

The submicron chromium dioxide(CrO2) thin film was fabricated on a poly-crystal titania(TiO2) film using Si wafers as substrates by atmospheric pressure chemical vapor deposition(CVD) method. X-Ray diffraction patterns show that the CrO2 films were pure rutile structure. Scanning electron microscopy(SEM) images indicate that the CrO2 films consisted of submicron grains with a grain size of 250–750 nm. The magnetic researches reveal that the magnetic easy axis is parallel to the films, and at room temperature, the CrO2 films show linear magnetoresistance.

Synthesis, characterization and mechanism of formation of carbon aerogels incorporated with highly crystalline lanthanum oxychloride particles

Low-density monolithic carbon aerogels incorporated with highly crystalline lanthanum oxychloride (LaOCl) particles were successfully synthesized using a novel facile sol–gel method. The LaOCl-doped carbon aerogels were experimentally determined to be inorganic porous materials with a density of ∼260 mg cm−3, specific surface area of 465 m2 g−1, and average pore diameter of 28 nm. The embedded LaOCl particles were highly crystalline, having formed a tetragonal phase structure, and constituted up to 28.58% of the mass of the carbon aerogel. A sol–gel mechanism was proposed for the formation of the aerogel and included the acidity of a an aqueous lanthanum chloride solution and ring opening of propylene oxide as two key factors promoting the formation of wet La-doped resorcinol-formaldehyde gels and highly crystalline LaOCl particles.