Papers by Keyword: Dope

Abstract: Doped TiO2 nanotubes for lithium ion batteries have attracted extensive attentions over the recent years, owing to their better electrochemical performances than bare TiO2 nanotubes. The forms of doping are various, depending on different dopants and preparation methods. In this paper, the preparation methods of doped TiO2 nanotubes, the forms of doping and the impacts on electrochemical performances for LIBs are reviewed. Meanwhile, the mechanism of doping is described briefly. The new directions of research on this field are proposed.

Abstract: The influencing factors of the stability for the potassium ferrate (K₂FeO₄), including pH, alkalinity, O₃, KI, KClO₃, KCl, NaClO₃ and Na₂SiO₃, were studied in this work. The results showed that the K₂FeO₄ stability in water is best at about pH=10. The higher the alkalinity is, the stronger of K₂FeO₄ stability would be. The O₃ had no effect to improve the K₂FeO₄ stability. The K₂FeO₄ stability would be best in water with 15mmol/L NaClO₃, 10mmol/L Na₂SiO₃ and 9mol/L alkalinity. Under this condition, the K₂FeO₄ content would be 83.28% after 24h.

Abstract: TiO₂, as photosensitive materials, has attracted much attention owing to its potential application in the solution of environmental pollution during the past decades. Four doped TiO₂ systems were constructed and studied by using the first principle based Density Functional Theory .The results indicate that P-doped and N-doped TiO₂ all have better light absorption in the visible light area than pristine TiO₂ although the band gap of N-doped system reduced less. However, the band gap of F-doped and Cl-doped TiO₂ increase a little, which causing the absorption to decrease. We suggest from the results that the P atom and N atom are valuable in the modification of TiO₂.

Abstract: Ni-doped ZnO diluted magnetic semiconductors nanorods were successfully synthesized by hydrothermal method. The crystal structure, morphology, constituent elements and optical proprety of the products using this method were investigated via X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray energy dispersive spectrometry (XEDS) and ultraviolet-visible spectroscopy (UV-vis). The experiment results show that the morphology of samples were nanorods with good dispersion, all the diffraction peaks correspond to the wurtzite structure hexagonal phase, no other impurity phase appeare, and the Ni²⁺ ions successfully substituted for the lattice site and generate single-phase Zn_1-xNi_xO. The band gap increases firstly and reduces afterward with the increase of Ni²⁺contents.

Abstract: In this study, TiO₂ nanoparticles composites were prepared by the micro emulsion method, above of all samples were characterized by FT-IR, XRD. Photo activities of Fe-TiO₂, TiO₂ were evaluated by degradation of oil-bearing wastewater. The results show that the photo activity of Fe-TiO₂ was more than that of TiO₂; the best presence of iron ion dopants in TiO₂ was 0.04%. Used stearic acids as the surface modification agent, Fe-TiO₂ were modified by situ surface modification. The results showed that the optimum conditions of stearic acid-Fe - TiO₂ :Temperature (20°C), the modified time (45 min), the ratio modifier dosage tomagnetitemass (4%). Then we did the initial exploration of Fe-TiO₂ Powder that was modified by stearic acid.

Abstract: This dissertation aims at the preparation of the Nanometer zinc oxide doping with different elements via the method of microwave. After characterizing those pellets of prepared Nanometer zinc oxide through XRD and SEM, it illustrates that the structure of Nanometer zinc oxide is still 6 wurtzite with high purity and the size of its pellet is at an averages of 21.83nm.But different mixed elements will differentiate the pellets' diameter. Moreover, through defined the Methyl orange as the stimulating pollutant, and conducted the Catalytic performance test of the samples. And the result shows that the effect was the best when doped with only Titanium, followed by doped with both Titanium and Magnesium, and the worst was doped with only Magnesium. Keywords: Microwave heating, ZnO, Dope, Degradation rate

Abstract: The Ti/SnO₂-Sb electrode with/without Er were manufactured by Pechini’s method. The electrodes were characterized using SEM, EDS, XRD, FT-IR, the oxygen evolution potential test and their electro-catalytic abilities were evaluated though nitenpyram degradation. XRD and FT-IR results showed that the structure of the electrodes were Sn-base sosoloid without Er and Sb phases. The Er³⁺ iron entering the unit cell of SnO₂ (Sn⁴⁺) could cause the grain refinement, the surface enrichment of Sb and Er, stronger water absorbability, and higher anode potential. These consequently generated more active sites and less oxygen vacancies on the anode surface, leading the improving of the electro-catalytic performance. The grain refinement mechanism for Er doping may be ascribed to the increase of the surface composition supercooling, the acceleration of the SnO₂ generation rate, and the restrain of its growth rate.

Abstract: The S+Ce co-doped TiO₂ nanocomposite films deposited on glass substrate had been synthesized by the sol–gel dip-coating method. The as-synthesized samples were characterized using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and ultraviolet-visible (UV-vis) absorption spectra analysis technologies. The surface morphology and surface chemical composition of the S+Ce co-doped TiO₂ nanocomposite film had been primarily investigated. The results shows that the properties of doped TiO₂ thin films with different ions have close relations with the intrinsical properties of S and Ce doped ions, the absorption edge shifted towards visible light region and the water contact angle of the surface of the nanocomposite films with the water droplet was only 6°, indicating that the S+Ce co-doped TiO₂ nanocomposite film showed promising applications in the self-cleaning and other potential fields.

Abstract: One-dimensional nanostructured polypyrrole (PPy) nanofibers were electrospun using a solution of PPy/polyvinyl alcohol (PVA); and PVA was used as the carrier in order to improve processability of PPy. In order to improve the performance of nanofibers, PPy were chemically synthesized by using different dopants, such as toluene sulfonate (TSNa), dodecyl-benzene sulfonic acid sodium salt (DBSNa), dodecyl sulfonic acid sodium salt (DSNa) and di-(2-ethylhexyl) sulfosuccinate sodium salt (DEHS). The morphology, structure and electrical conductivity of the fabricated nanofibers was investigated using SEM, FTIR and four-probe method, respectively. The results show that the diameters of doped PPy/PVA nanofibers are in the range of 50-190 nm. The electrical conductivity of the obtained doped PPy/PVA nanofibers was about 161-222 S/cm. DEHS doped PPy can not only make the obtained PPy be soluble in some organic solvents, but also improve the electrical conductivity of nanofibers when it is compared with that of TSNa, DSNa, DBSNa as dopants.

Abstract: Europium doped tantalum oxide (europium-Ta₂O₅) particles were synthesized with a low temperature hydrothermal method. The electrochemical behaviour of an europium-Ta2O5 film electrode in 0.1 mol dm^-3 KCl solution containing 5 mmol dm^-3 K₃Fe(CN)₆ was investigated using cyclic voltgrammetry (CV). The CV results indicated that the europium-Ta₂O₅ film electrode exhibited good stable and reversible electrochemistry properties. The electrochemical reaction of K₃Fe(CN)₆ was a diffusion-controlling process on the europium-Ta₂O₅ film electrode. The europium-Ta₂O₅ particles might have potential applications in electrochemical fields.