Advanced Materials Research Vol. 465

Abstract: The complex fluoride BaNiF4:Ce3+ was synthesized by reflux method using ethylene glycol as reaction solvent at its boiling point temperature. The sample was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and fluorescence spectrophotometer. The results indicated that the mean particle diameter of BaNiF4:Ce3+ was 53.8 nm. Only adsorption oxygen (α oxygen) existed on the surface of BaNiF4: Ce3+ and the content of surface oxygen was ≤5%. The maximum emission peak of BaNiF4:Ce3+ was 350 nm in its luminescent spectrum, and emission band of Ce3+ belonged to 5d→4f transition.

Abstract: The Ni-SiC nano-composite coatings were prepared on the ring of stainless steel by using of high frequency pulse electroplating. Orthogonal experiment was used to study optimal dosage of the dispersant. The effect of some factors, such as current density, pH value, temperature , addition agent and so on, were studied. The characterization of Ni-SiC nano-composite coatings were studied by wear test. The effect of pulse frequency and the SiC concentration in the electrolyte on the wear resistance of Ni-SiC nano-composite coatings were studied. The morphology of the nano-composite coatings in wear test before and after were analyzed by SEM and the metaloscope photographs. The results show that Ni-SiC nano-composite coatings of high frequency pulse electroforming have better performance of wear resistance.

Abstract: The core/shell structured rutile/apatite was prepared by soaking rutile TiO2 (R-TiO2) microspheres into a simulated body fluid (SBF) only for 1 day. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) and N2 adsorption measurements. XRD showed that the apatite content increased with prolonging the soaking time or increasing the SBF concentration. TEM and EDX demonstrated that apatite had been coated on the surface of R-TiO2 microspheres successfully. HRTEM indicated that the lattice spacings of 0.27 nm and 0.32 nm were assigned to (211) plane of apatite and (101) plane of R-TiO2, respectively.

Abstract: A series of nanocrystalline FeNbB films were fabricated using ion-beam sputtering technique from FeNbB target. Pieces of these films were annealed for 1 hour at various temperatures up to 5730C. Room temperature soft magnetic properties of these films were measured. The influence of microstructure on magnetic behavior in nanocrystalline FeNbB films is investigated in a series of specimens with different film’s thickness. For the sample 120nm and 5000C annealed, cutoff frequency was found to be 5E7 Hz, which has the μf0=5E10.

Abstract: The novel Y2O3 nanoflowers were synthesized through a facile hydrothermal method without using any catalyst or template. The phase composition and the microstructure of as-prepared products were characterized by field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD) as well as Fourier transform infrared spectrum. The formation mechanism for the Y2O3 flowers has been proposed.

Abstract: Anatase nano-TiO₂ film was prepared by sol-gel method and graphene oxide nanosheets synthesized by Hummers method were deposited on this TiO₂ thin film. Another nano-TiO₂ film was then deposited on the graphene film forming sandwich-like to avoid graphene layer peeled off. Scanning electron microscope shows that TiO₂ particles layer with a diameter of about 20 nm were densely and uniformly deposited on both surfaces of the graphene layer to form a sandwich-like composite structure. The composite films exhibit excellent photocatalytic degradation to methyl orange and remains chemically stable in the whole process without anything exfoliation.

Abstract: With the development of science and technology, the smaller sizes generator, the more attention by people. The main purpose of this article is to manufacture three-phase nanogenerator and piezoelectric nanogenerator under vibration, and their working principle are introduced and their performances are studied. The results show that, using the present nanomaterials, three-phase nanogenerator and piezoelectric nanogenerator can be prepared. In ambient vibration condition, piezoelectric materials produce larger rated current and voltage. However, copper laps cutting magnetic line of force produce less rated current and voltage. So the piezoelectric nanogenerator can be separately used to supply power. It may produce higher voltage, current and power if three-phase nanogenerator and piezoelectric nanogenerator in series-parallel connection, and there is commercial value.

Abstract: In this paper, electrochemical polymerization method was used to prepare electrochromic PANI films with different thicknesses via changing the polymerization time. It is found that the obtained PANI films are uniform and have good adherence with the ITO bases. Scanning electron microscope (SEM) images further show that the obtained films exhibited the tremella like lamellar structures with the diameter of each leaf about 100nm and the thickness of about 20nm at polymerization time of 8min. Optical electronic tests indicated that the films showed a gradient color variation from pale yellow, light yellow to green, blue-green, blue and dark blue among -0.2V and 1.0V. Furthermore, the color saturation increased and the hues became more abundant as polymerization time extended. The optical contrast ratios (ΔT) firstly increased to the maximum of 35% and then decreased, while the response time became longer. The results illustrate that the different shades of color are probably obtained through electrochemical polymerization method, which is important for the preparation of RGB full color system.

Abstract: Amino functionalized mesoporous silica gel was synthesized, characterized and used as adsorbents for low concentration of Mn2+ and Co2+ simulating the 60Co2+ and 56Mn2+ in low-level radioactive wastewater. The adsorption capacities with different contact time and at pH were calculated. Three adsorption isotherms were employed, and the Sips model described the adsorption best, the maximum adsorption capacities for Co2+ and Mn2+ calculated by this model were 0.377mmol/g and 0.384mmol/g respectively. The competitive experiments showed that the affinity between adsorbents and metal ions is different. The adsorbents retained Co2+ much easier. Dynamic adsorption experiments were carried out in a fixed bed column which suffered a decrease of adsorption capacity than statistic experiments.

Abstract: Carbon nanofibers with novel morphology are successfully synthesized by the chemical vapor deposition of acetylene with dendritic copper nanocrystals on Cu electrode as a catalyst. Growth mechanism of sandwich-like and multi-branched carbon fibers is discussed, and the impact of catalyst morphology and growth time on the structure of the carbon nanofibers is investigated. The organic groups and the thermal stability of the as-prepared carbon nanofibers are revealed by Fourier transform infrared spectrum (IR) and thermogravimetric (TG) analysis.