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oe1(光电查) - 科学论文

162 条数据
?? 中文(中国)
  • Synthesis of Urchin-like and Yolk-shell TiO <sub/>2</sub> microspheres with enhanced photocatalytic properties

    摘要: The novel urchin-like and yolk-shell titania microspheres (henceforth called UYTMs) with nanowires/microspheres hierarchical structures were successfully synthesized by a synthetic sol-gel and hydrothermal method without using any template. Uniform TiO2 microspheres were firstly prepared by the sol-gel method, and the great monodispersed properties was delicately regulated by using the surfactant of KCl, aniline and a proper amount of water. The urchin-like yolk-shell morphology was further achieved by a NaOH-assisted hydrothermal process, and the diameter and shell thickness of the UYTMs were highly controlled by the concentration of NaOH. The detailed morphology, chemical composition and crystallinity of the UYTMs were systematically characterized by several techniques, and the underlying formation mechanisms was attentively discussed as well. The photodegradation of methylthionine chloride experiments indicated the UYTMs showed much better photocatalytic activity than that of commercial P25. This is mainly because the UYTMs exhibited much more reactive sites, higher adsorption ability and tuned optical absorption behavior owing to their large specific surface area, hierarchical structures and the special hollow yolk-shell structure.

    关键词: Titania,NaOH-assisted hydrothermal synthesis,Photocatalytic activity,Yolk-shell,Urchin-like microspheres

    更新于2025-09-10 09:29:36

  • Effects of Pt-loading on Formation and Visible Light-Induced Photocatalytic Activity of Bismuth Titanate

    摘要: Pt/TiO2-Bi2O3 test catalysts were prepared by impregnating Pt on the sol-gel derived TiO2-Bi2O3 to give these testpieces high photocatalytic activity under visible light irradiation. The optimum Pt support content and TiO2 content were observed in the ranges 0.05-0.3 wt% and 17-28 wt%, respectively in the photocatalytic activity for Methylene Blue (MB) degradation on Pt/TiO2-Bi2O3. Specifically, those 0.1Pt/17TiO2-83Bi2O3, 0.2Pt/23TiO2-77Bi2O3 and 0.3Pt/28TiO2-72Bi2O3 samples showed relatively higher photocatalytic activity for the MB degradation. The results were closely related to (1) the restriction of recombination of the photo-induced electron and hole pairs by Pt, and (2) the presence of bismuth titanate with such high Ti content as built up by Pt.

    关键词: Bismuth titanate,Pt-loading,Methylene Blue degradation,Photocatalytic activity,Nucleating agent

    更新于2025-09-10 09:29:36

  • Investigation of structural, optical and electrical properties of transition metal oxide semiconductor CdO ZnO nanocomposite and its effective role in the removal of water contaminants

    摘要: In this technological era as the usage and development of technology is on the rise we encounter serious repercussions of pollutions in both drinking and daily usage of water. Nanocomposite of Cadmium Oxide and Zinc Oxide (CdO-ZnO) has the property of alienating the pollutants from the water. A conventional hydrothermal method was adapted for the preparation of nanocomposite of CdO-ZnO from their respective metal acetate dihydrates and NaOH. Structural and morphological analysis by electron beam diffraction technique reveals the formation of unique nanorod with spherical morphology of the synthesized particle. Williamson-Hall method was used to find the crystallite size and the lattice strain. Fourier transforms infrared (FTIR) spectroscopy further confirmed the stretching and vibration of chemical bonds of the materials. The study of electronic transitions within the material was portrayed with UV-Vis absorption spectrum and the obtained energy gap is 3.99 eV. A thorough investigation of temperature dependent electrical properties of CdO-ZnO nanocomposite was carried out in the frequency range from 50 Hz to 5 MHz. Studies revealed that the composite material is responsible for higher photocatalytic performance under the irradiation of UV photon. The high photocatalytic activity was originated from superoxide O2? radicals due to the efficient trapping of photogenerated electrons in CdO by ZnO.

    关键词: Zinc Oxide,Williamson-Hall method,Photocatalytic Activity,Cadmium Oxide,Electron Beam Diffraction

    更新于2025-09-10 09:29:36

  • Fabrication of Gd-La codoped TiO2 composite via a liquid phase plasma method and its application as visible-light photocatalysts

    摘要: TiO2 was doped simultaneously with Gd and La using a liquid phase plasma (LPP) reaction to produce a photocatalyst with excellent photoactivity in the visible light region. Gadolinium chloride hexahydrate and lanthanum chloride heptahydrate precursors were used to dope the TiO2 powder with polycrystalline Gd2O3 and La2O3 particles. The doping of TiO2 with rare earth elements using LPP reaction decreased the band gap; the band gap of Gd-La codoped TiO2 photocatalysts (GLTP) was the lowest. The photodegradation efficiency of the TiO2 photocatalysts doped with either Gd or La was superior that of bare TiO2 but the photodegradation efficiency of GLTP was highest in both ultraviolet and visible light sources. Acetaminophen (Acetyl-para-aminophen, APAP) was ultimately decomposed to CO2 and H2O via intermediates, such as p-nitrophenol, hydroquinone and hydroxylhydroquinone, by hydroxyl radicals (HO?) formed on the surface of GLTP.

    关键词: Liquid phase plasma,Gd-La codoped TiO2 photocatalysts,Band gap energy,Acetaminophen,Photocatalytic activity

    更新于2025-09-10 09:29:36

  • Enhanced Visible Photocatalytic Activity of Tree-like ZnO/CuO Nanostructure on Cu Foam

    摘要: Novel tree-like ZnO/CuO composite, composed of CuO nanowire trunks and ZnO nanorod branches, have been successfully synthesized on Cu foam substrate. Single-crystalline CuO nanowires and ZnO nanorods are obtained by thermal oxidation and hydrothermal processes, respectively. The morphological, crystal and optical properties of the as-prepared samples have been studied by field-emission scanning microscopy, X-ray diffractometer, transmission electron microscopy, and UV-vis spectrophotometer. The resultant tree-like ZnO/CuO composites on Cu foam show excellent photocatalytic activity with a rate constant of about 0.0073 min-1 in the photo-degradation of Rhodamine B (RhB) under visible light (λ>420 nm). The Cu foam not only provides extra-large surface area for the growth of tree-like CuO/ZnO composites, but also acts as an effective frame to support the catalysts. Furthermore, tree-like ZnO/CuO composite catalysts show high recovery yield for the recycling during the degradation of organic pollutants. This work provides an insight view into the design and synthesis of composite photocatalyst effectively supported by a substrate.

    关键词: Cu foam,ZnO/CuO composite,self-supported photocatalyst,visible photocatalytic activity

    更新于2025-09-10 09:29:36

  • Synthesis of TiO <sub/>2</sub> (B) and High-temperature Stable Anatase TiO <sub/>2</sub> Nanowires by Hydrothermal Method and Investigation of Photocatalytic Activity

    摘要: In this study, TiO2 nanowires (TNWs) were synthesized through hydrothermal method and were characterized using X-Ray diffraction (XRD), transmission electron microscopy (TEM) and BET techniques. Monoclinic TiO2 (B) is the dominant phase of TNWs up to 600 ℃ which is completely transformed into a highly crystalline anatase phase at 800 ℃. The photocatalytic activity of TNWs, prepared at various calcination temperatures, was investigated in the removal of Rhodamine B (RhB) as an organic model pollutant. The results indicated that the photocatalytic activity of TNWs, prepared at 800 ℃ calcination temperature (TNWs-800), was better than that of other samples and even TiO2-P25 nanoparticles.

    关键词: Anatase TiO2 nanowires,Photocatalytic activity,TiO2 (B),Hydrothermal method,High-temperature

    更新于2025-09-10 09:29:36

  • Synthesis and Photocatalytic Activity of Nanosized Powder of Zn-Doped Titanium Dioxide

    摘要: Nanosized powder materials made Zn-doped titanium dioxide with concentration of 0.1, 0.5, and 1.0 mol % Zn2+ have been synthesized from aqueous solutions of inorganic compounds of titanium modified with zinc(II) ions. The materials obtained have been studied by electron microscopy, thermogravimetric analysis, and powder X-ray diffraction. It has been found that if zinc ions introduced in titanium dioxide the stabilization of anatase modification takes place retaining size and morphology of particles. The materials synthesized have shown photocatalytic activity under ultraviolet and visible light irradiation. The highest photocatalytic activity has been found for material containing 0.1 mol % Zn2+ and calcined at 600°С.

    关键词: photocatalytic activity,nanoparticles,titanium dioxide,nanomaterials

    更新于2025-09-10 09:29:36

  • Mineralization of toxic industrial dyes by gallic acid mediated synthesized photocatalyst SnO2 nanoparticles

    摘要: This is the first report on gallic acid mediated synthesis of tetragonal rutile tin oxide (SnO2) nanoparticles (NPs) and their photocatalytic activity towards organic dye methylene blue (MB), sunset yellow (SSY) and carmoisine A (CA) under 254 nm UVC irradiations. The crystal structure and crystallite size of SnO2 NPs was confirmed by X-ray diffraction (XRD) studies. The SnO2 NPs mean diameter of 9 nm was obtained by transmission electron microscopy (TEM) analysis. The photoluminescence and absorption studies were carried out by using fluorescence and UV-Vis spectrophotometers. Its band gap was found to be 3.1 eV. The photocatalytic studies have explored the potential of SnO2 NPs towards mineralization of three dyes, which was confirmed by using UV-Vis spectrophotometer and total organic carbon (TOC) analyzer. Our results show that all three dyes were degraded 100% within 50 min under UVC irradiation which suggest its promising capacity in alleviating environmentally pollutant dyes.

    关键词: photocatalytic activity,SnO2 NPs,TOC,Gallic acid,photoluminescence

    更新于2025-09-10 09:29:36

  • The preparation and photocatalytic performance research of CdSe and wool ball-like GO/CdSe microspheres

    摘要: Different morphologies of CdSe and GO (graphene oxide)/CdSe microspheres like wool ball and walnut shape have been made through hydrothermal method using CTAB as surfactant. X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), X-ray energy dispersive spectrometer (EDS), scanning electron microscope (SEM), Raman spectra, and UVevis absorption spectrum, were used to intensively investigate the structures, morphologies, chemical compositions and optical properties of CdSe and GO/CdSe microspheres. The results of XRD revealed that GO/CdSe microspheres have lead-zinc mineral structure. The results of XRD, EDS, XPS and Raman spectra showed that GO/CdSe microspheres were grown on GO sheets. Also UVevis absorption spectrum indicated that GO/CdSe microspheres enhanced absorbance in UV light region and visible light region. Through comparative experiments, the results showed that pH ? 4 is the optimal pH value for degrading Rhodamine B (RhB) solution. To study the photocatalytic performance of GO/CdSe microspheres, we catalyzed the degradation of RhB aqueous solution irradiated by visible light. The photocatalytic results showed that the wool ball-like GO/CdSe microspheres exhibited better photocatalytic activity than rough CdSe.

    关键词: GO/CdSe microspheres,Hydrothermal method,Morphologies,GO,Photocatalytic activity

    更新于2025-09-10 09:29:36

  • Pronounced Visible Light Photocatalytic Activity Obtained from Coupling of TiO<sub>2</sub> with Metal Organic Macromolecule

    摘要: In this work, a new catalyst TiO2@MOM has been successfully synthesized by coupling TiO2 with metal organic macromolecule (MOM) through hydrothermal-solvothermal two-step process. Having a high visible photocatalytic activity considerably superior to that of single TiO2, the fabrication of TiO2@MOM should provide a new way of upgrading the TiO2–based catalyst.

    关键词: Photocatalytic activity,TiO2,Metal organic macromolecule

    更新于2025-09-10 09:29:36