Papers by Keyword: Photocatalytic Property

Abstract: Flower-like TiO₂ hierarchical structures were synthesized by a solvothermal strategy using tetrabutyl titanate as the titanium source. The obtained flower-like TiO₂ hierarchical structures were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), specific surface area analysis, Raman spectroscopy and energy-dispersive spectroscopy (EDS). Results show that the flower-like hierarchical structures are composed of anatase titanium dioxide. TiO₂ nanowires are first formed by the self-assembly of nanocrystals with a diameter of 20 nm, and then several TiO₂ nanowires produce a petal-like structure. Finally, flower-like TiO₂ hierarchical structures with a diameter of 2 ~ 2.3 μm are assembled by these petal-like structures. The electrochemical properties of the flower-like TiO₂ hierarchical structures were studied by using these hierarchical structures as the anode material in a lithium-ion battery. The flower-like TiO₂ hierarchical structures have an initial discharge capacity of 473.9 mAh/g at a current density of 100 mA/g and an initial discharge capacity of 244.4 mAh/g at a current density of 2 A/g in the potential range of 0.01~3 V. The photocatalytic properties of the flower-like TiO₂ hierarchical structures were studied by degrading methyl orange (MO) solution under ultraviolet (UV) light irradiation. When used as a photocatalyst, the degradation rate of MO is 95.8% after 40 min of UV irradiation, showing that the flower-like TiO₂ hierarchical structures have excellent photocatalytic activity.

Abstract: In this paper, the effect of nanoTiO₂ content on the thermal properties, mechanical properties, photocatalytic properties of PA6/TiO₂-GO composites were investigated. The results indicated that the melting point of the composites decreased gradually with an increase of nanoTiO₂ content, and the degree of crystallinity exhibited an increasing trend at first and then tended to decrease. Meanwhile, the breaking strength decreased gradually, whereas the elongation at break increased gradually. Moreover, the nanoTiO₂ exhibited an increasing photocatalytic activity for degradation of the methylene blue solution. The incorporation of graphene oxide (GO) could effectively improve the photocatalytic effectiveness of nanoTiO₂ by approximately 11%.

Abstract: Photocatalytic technology is widely used in water purification because of its environmental protection, high efficiency and energy saving. Therefore, it is extremely important for the selection and preparation of specific semiconductor materials used in the field of photocatalysis. In this work, 1T@2H MoS₂ nanosheets were fabricated by simple hydrothermal method, and the photocatalytic property of as-prepared 1T@2H MoS₂ were investigated by the photo-degradation of methylene blue (MB) water solutions under visible light irradiation via 2H MoS₂.The results indicated that compared to 2H MoS₂, the 1T@2H MoS₂ exhibited more excellent photocatalytic degradation property. After 150 minutes of irradiation under visible light, 1T@2H MoS₂ had a removal rate of 98% for MB, and 2H MoS₂ eventually reached 19%. The enhancement photocatalytic property of 1T@2H MoS₂ could be attributed to the reduced band gap energy of the hybrid-nanosheets and the increased in electron migration speed.

Abstract: SO₄^2-/TiO₂, SO₄^2-/Fe₂O₃ nanoparticles were prepared by the impregnation precipitation method. The X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy disperse spectroscopy (EDS) results showed that the uniform size of SO₄^2-/TiO₂, SO₄^2-/Fe₂O₃ nanoparticles with high purity, good dispersivity and particle size range from 50nm to 200nm. A comparative study between SO₄^2-/TiO₂ and SO₄^2-/Fe₂O₃ nanoparticles applied in the photocatalytic experiment on unsymmetrical dimethylhydrazine (UDMH) wastewater was carried out.

Abstract: In this study, we synthesized the TiO₂-modified hydroxyapatite (HAp) with various morphologies by hydrothermal treatment using urea decomposition, at 160 oC for 6 h. After hydrothermal treatment, carbonate-substituted HAp and TiO₂ (anatase) phases were formed in products using 1.0-0.1 M urea solution. The morphology of synthesized HAp changed from small plate-shaped to long needle-shaped crystals with decreasing the urea concentration. The photocatalytic property for samples was investigated by decoloration test using 25 ppm methylene blue solution. In comparison with HAp samples without TiO₂, the TiO₂-modified HAp clearly showed the photocatalytic decomposition of methylene blue by UV irradiation.

Abstract: In this paper, low-temperature preparation of rice husk char/TiO₂ composite was developed by utilizing agriculture waste. nanosized TiO₂ particles were successfully loaded to rice husk char by in-situ thermal treatment of impregnated rice husk. The structural characteristics and photocatalytic activities of obtained composites were investigated. The specific surface area of rice husk char was enlarged due to the catalytic effect of loaded TiO₂ during thermal treatment. The porous rice husk char matrix combined with nanosized TiO₂ particles offered large specific surface area and good photocatalytic property. This low-temperature preparation method provided a promising way to reuse the waste biomass and extended the applications of charcoal.

Abstract: Structural, optical and photocatalytic properties of ZnO powders prepared by a precipitation method were systematically investigated by means of X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis diffuse reflectance measurement and UV-Vis absorbance measurement. The antibacterial activity was tested by a broth microdilution method. All calcined ZnO powders exhibited a hexagonal wurtzite structure. The ZnO powders formed various shapes depending upon the concentration of n-propylamine used. The E_g value of ZnO powders depended upon defect concentration. The photocatalytic property of ZnO powders depended on the particle shape and defect concentration. The best photocatalytic efficiency of 100% was observed from the ZnO powders prepared at R = 2 after irradiating by the blacklight for 90 min. All ZnO powders can damage only S. aureus and the agglomerated sheet-like ZnO powders prepared at R = 2 showed the best antibacterial property with a MIC value of 1.5625 mg/mL.

Abstract: In this paper, α-Fe₂O₃ photocatalyst with high photocatalytic activity (IL-α-Fe₂O₃) was fabricated via hydrothermal routine using 1-ethyl-3- methylimidazolium dihydrophosphate ([EMIm]H₂PO₄). The specific surface area, structure, the photo-induced charge separation rate were characterized by Brunauer-Emmett-Teller (BET) measurements, X-ray diffraction (XRD), and surface photovoltage spectroscopy (SPS), respectively. The results show that adding ([EMIm]H₂PO₄ into the synthetic system alters the specific surface parameters and photo-induced charge separation rate. The photocatalytic activity for decolorization of methyl orange (MO) solution was investigated. The results show that the photocatalytic activity of IL-α-Fe₂O₃ is more than 2.5 times that of the reference α-Fe₂O₃ and the underlying mechanisms are discussed.

Abstract: The self-organized oxide nanotube/pore layers were prepared by anodization on ternary Ti-6Al-4V alloys. The morphologies and structures of layers under different heat treatment tempreture were characterized by means of SEM, XRD, XPS and Raman spectroscopy and DRS. The effects of alloying element under different heat treatment tempreture on the structure, composition and opsorption property of the film catalysts were investigated along with their inherent relationships. The results show that two kinds of Ti-Al-V-O nanostructure grown inthe α and β phase region formed on the surface of the alloy. V doped-TiO₂ can inhibit the formation of anatase. The films show the microcrystalline structure of anatase and rutile and a small amount of V₂O₅ on the surface of film annealed at 400 oC. Moreover, the large surface and the synergy effect of V-doped TiO₂ and V₂O₅ make sample show the highest photocatalytic activity for the photocatalytic hydrogen evolution.

Abstract: A 1-D chain-like POM - based organic-inorganic hybrid compound with the chemical formula of [Ni (en)₂]{[Ni (en)₂]₂[Mo₈V₈O₄₀(VO₄)]}[(NH₂)₂(C₂H₄)₂NH]₂·2H₂O (en = ethylenediamine) (1) has been hydrothermally synthesized and structurally characterized by the elemental analysis, and single crystal X-ray diffraction. Compound 1 consists of the bi-supported tetra-capped Keggin-type {[Ni (en)₂]₂[Mo₈V₈O₄₀(VO₄)]}^2- building blocks and [Ni (en)₂]²⁺ metal organic cationic moieties are connected together to form 1-D chain through covelent-bonding interactions, which is further linked into 3-D supramolecular networks . The degradation of methylene blue (MB) under UV irradiation with 1 as the heterogeneous photocatalyst has been investigated, showing a good photocatalytic property of 1 for MB degradation.