Papers by Keyword: Ag Doping

Abstract: In this study, silver-doped zinc oxide (ZnO) nanorods were grown by a solution method and the effect of varying the doping concentration on the electrical property and component characteristics of the synthesized ZnO nanorods were studied. The ZnO nanorods were grown in the mixed solution of zinc nitrate hexahydrate (Zn (NO₃)₂·6H₂O), hexamethylenetetramine (C₆H₁₂N₄), and silver nitrate (AgNO₃) at 90^oC for 2 hours. The purpose of silver nitrate was to supply dopant atoms. Field-emission scanning electron microscopy (FE-SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) were used to investigate the surface morphology, chemical compositions, and microstructure of silver-doped ZnO nanorods, and the electrical properties were determined by Hall effect measurement. As found by EDS results, dopant atoms Ag have been successfully incorporated into the crystalline structure of ZnO nanorods, and the conductivity, concentration and mobility of majority carrier in ZnO nanorods have been modified accordingly.

Abstract: Ag-doped BiVO₄ semiconductor photocatalysts were synthesized via the one-step hydrothermal method. The microstructure and morphology of catalysts were characterized by using X-ray diffraction, Scanning electron microscopy, and Energy dispersive X-ray detector (EDS) and photocatalytic activities of BiVO₄ catalysts with and without Ag doping were evaluated by degrading methylene blue (MB) under visible-light irradiation. UV-Vis absorption spectra were measured to evaulate the photocatalytic activity of the as-synthesized catalysts. The results suggested that Ag-doped BiVO₄ with larger rod-like particle size but better crystallnity has the stronger UV absorption. In comparison with pure BiVO4, degradation rate of MB was increased about 18% in Ag-doped BiVO₄ with the Ag⁺ dopant concentration of 15 mol%.

Abstract: Ag surface doped TiO₂-SiO₂ composite films had been synthesized by the sol-gel method and doping processes, in which tetrabutyl titanate (Ti(OC₄H₉)₄) and tetraethylorthosilicate (TEOS) were chosen as the precursors and silver nitrate (AgNO₃) was chosen as silver source. The experimental results revealed that the Ag surface doped TiO₂-SiO₂ composite film was composed of uniform round-like nano-particles or aggregates with the size range of 4–10 nm. Compared with pure TiO₂ film, Ag surface doped TiO₂-SiO₂ composite film exhibited excellent photocatalytic activity. It is believed that the microstructure of the composite film is responsible for improving the photocatalytic activity.

Abstract: It has been proven that HA coatings on implant materials treated with silver exhibited excellent antibacterial effects. Silver (Ag) ions were successfully incorporated into HA structure with the precipitation method. Although this method was pretty much suitable for the synthesis in powder form, it is not applicable to in-situ coating processes. The aim of the current study is to synthesize Ag ion incorporating HA via the decomposition of EDTA Chelate. For this reason, Ag doped crystalline-sodium and carbonate-containing HA solutions will be prepared using calcium-EDTA in a sodium phosphate solution, hydrogen peroxide and silver nitrate. As the source of Ag ions, silver nitrate was added into the solution in the desired proportions. Then, the samples were sintered at temperatures from 800oC to 1100oC and characterized with XRD and SEM.

Abstract: Silver-doping in SnS films can improve the semiconducting properties of SnS films. Based on our previous research, SnS:Ag thin films were deposited on ITO coated glass by pulse electro-deposition in order to study their structural, optical and electrical properties. SnS:Ag thin films were characterized with X-ray diffraction (XRD) , Scanning Electron Microscope (SEM) and some other methods. The primary composition of the films is SnS, but maybe there is a little quantity of SnS2, Ag8SnS6 and other compounds. The doped films exhibit good crystallization with big grain size. They have an optical gap of 1.66~1.89eV and a high absorption coefficient (α＞5×104cm-1). Hall measurement has shown that all the samples are of p-type conduction with low resistivity of the order of 10-3Ω•cm, and the carrier concentration increases to 1019cm-3 after Ag-doping. In conclusion, the semiconducting properties of the SnS films have been improved by silver-doping. Thus, SnS:Ag thin films can be used as solar cells absorbers.

Abstract: Ag-doped hydroxyapatite films were deposited on a ZrO2 substrate using r.f. magnetron sputtering to improve the bioaffinity and mechanical properties of the hydroxyapatite. The resulting hydroxyapatite films exhibited a variation in their microstructure and mechanical properties relative to the Ag content. The variation in the (Ca, Ag)/P ratios suggested that some of the Ca2+ ions in the hydroxyapatite were replaced with Ag+ ions. After annealing at 800oC, the hydroxyapatite films showed a microstructure with crystalline nano-grains, whereas the Ag-doped hydroxyapatite films revealed the formation of crystallites embedded in the amorphous matrix. The hydroxyapatite films showed an average roughness of about 3~4nm, very smooth surface, and dense microstructure. The hardness and modulus of the films decreased with an increasing Ag content.