Preparation of Ultrafine TiO2 Nanofibers and their Application in Removal of NOx in Air

2008 ◽  
Vol 569 ◽  
pp. 25-28 ◽  
Author(s):  
Kannikar Juengsuwattananon ◽  
Pim On Rujitanaroj ◽  
Pitt Supaphol ◽  
Nuttaporn Pimpha ◽  
Sadao Matsuzawa
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Average Diameter ◽  
Ethanol Solution ◽  
Catalyst Loading ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
Tio2 Nanofiber ◽  
Transmission Electron ◽  
Titania Precursor

Titanium dioxide nanofibers were fabricated by electrospinning technique. The titania solutions were obtained from adding various types of Ti precursor (Ti(OBu)4, Ti(OiPr)4, and Ti(OPr)4) to an ethanol solution containing polyvinyl pyrrolidone (PVP). Acetic acid was used to stabilize the solution and to control the hydrolysis reaction. The porous and well-defined crystalline structure was obtained after calcined at 450oC for 1 h. The thermal behavior, phase composition including crystallite size, as well as the morphology of as-synthesized nanofibers was obtained from thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The average diameter of these nanofibers was in the range from 100 to 400 nm depending on titania precursor. The photocatalytic activity of TiO2 fibers were evaluated for NOx degradation in a gaseous phase. The results demonstrated that at the same catalyst loading, the photocatalytic activity of TiO2 nanofiber was higher than the commercial Degussa P-25.

scholarly journals Electrospinning Preparation and Photocatalytic Activity of Porous TiO2Nanofibers

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Shanhu Liu ◽  
Baoshun Liu ◽  
Kazuya Nakata ◽  
Tsuyoshi Ochiai ◽  
Taketoshi Murakami ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Uv Light ◽  
Ethanol Solution ◽  
Titanium Tetraisopropoxide ◽  
X Ray Diffraction ◽  
Carbon Nanospheres ◽  
Transmission Electron ◽  
Electrospinning Method ◽  
Subsequent Calcination

Porous TiO2nanofibers were prepared via a facile electrospinning method. The carbon nanospheres were mixed with the ethanol solution containing both poly(vinylpyrrolidone) and titanium tetraisopropoxide for electrospinning; and subsequent calcination of as-spun nanofibers led to thermal decomposition of carbon nanospheres, leaving behind pores in the TiO2nanofibers. The morphology and phase structure of the products were investigated with scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Furthermore, the photocatalytic activity of porous TiO2nanofibers was evaluated by photodecomposition of methylene blue under UV light. Results showed that the porous TiO2nanofibers have higher surface area and enhanced photocatalysis activity, compared to nonporous TiO2nanofibers.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

scholarly journals A comparative study on the VOCs sensing behaviors of various ZnO nanostructures

2020 ◽  
Vol 9 (4) ◽  
pp. 117-122
Author(s):  
Vuong Nguyen Minh ◽  
Dung Dinh Tien ◽  
Hieu Hoang Nhat ◽  
Nghia Nguyen Van ◽  
Truong Nguyen Ngoc Khoa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hierarchical Structure ◽  
Hydrothermal Process ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
Electrospinning Technique ◽  
Transmission Electron ◽  
Volatile Organic ◽  
Wet Chemical

The volatile organic compounds (VOCs) sensing layers were studied using ZnO nanomaterials with different morphologies including hierarchical nanostructure (ZnO-H), nanorods (ZnO-NRs), commercial nanoparticles (ZnO-CNPs) and wet chemical synthesized nanoparticles (ZnO-HNPs). ZnO hierarchical structure was fabricated by an electrospinning technique followed by hydrothermal process. ZnO vertical nanorods structure was fabricated by hydrothermal method, while ZnO nanoparticles based sensors were prepared from commercial powder and wet chemical method. The morphology and properties of the fabricated samples were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). VOCs sensing responses toward acetone, ethanol and methanol with respect to altered ZnO nanostructureswas systematically compared at different working temperatures. The enhanced response at low working temperatures induced by theopen space hierarchical structure was observed. The VOCs sensing mechanisms of the ZnO nanostructures based sensing layer were also explained and discussed in detail. 

scholarly journals Oxide-Clay Mineral as Photoactive Material for Dye Discoloration

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 132
Author(s):  
Maicon O. Miranda ◽  
Bartolomeu Cruz Viana ◽  
Luzia Maria Honório ◽  
Pollyana Trigueiro ◽  
Maria Gardênnia Fonseca ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Clay Mineral ◽  
Uv Light ◽  
High Photocatalytic Activity ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Zirconium Oxides ◽  
Transmission Electron ◽  
Palygorskite Clay

Titanium and zirconium oxides (TiO2 and ZrO2, respectively) were obtained from alkoxides hydrolyses, and then deposited into palygorskite clay mineral (Pal) to obtain new materials for photocatalytic applications. The obtained materials were characterized by structural, morphological, and textural techniques. X-ray diffraction (XRD) results confirmed the characteristic peaks of oxides and clay transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of the modified palygorskite with both oxides showed that the clay was successfully modified by the proposed method. The increase in the specific surface area of the clay occurred when TiO2 and ZrO2 were deposited on the surface. The photocatalytic activity of these materials was investigated using the Remazol Blue anion dye under UV light. The evaluated systems presented high photocatalytic activity, reaching approximately 98% of dye discoloration under light. Thus, TiO2–Pal and ZrO2–TiO2–Pal are promising clay mineral-based photocatalysts.

Nanofibres of Ceramic Compounds by Electrospinning

2006 ◽  
Vol 45 ◽  
pp. 735-740 ◽  
Author(s):  
W. Nuansing ◽  
S. Maensiri
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
Thermoelectric Oxide ◽  
Electrospinning Technique ◽  
Experimental Procedure ◽  
Transmission Electron ◽  
Set Up ◽  
Ceramic Compounds ◽  
Typical Process

This paper reports on the fabrication of nanofibres of ceramic compounds using electrospinning technique. In a typical process, ceramic nanofibres are fabricated by electrospinning a precursor mixture of appropriated metal sources, polymer and solvent, followed by calcination treatment of the electrospun composite nanofibres. In this work, the electrospinning set up as well as experimental procedure are described in detail. The fabrication of thermoelectric oxide NaCo2O4, ferroelectric Ba1-xSrxTiO3 and semiconductor TiO2 nanofibres with diameter of ~20-200 nm are demonstrated. The characterization of the fabricated nanofibres using TG-DTA, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy is also investigated.

scholarly journals Electrospinning Synthesis and Photocatalytic Activity of Mesoporous TiO2Nanofibers

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jing Li ◽  
Hui Qiao ◽  
Yuanzhi Du ◽  
Chen Chen ◽  
Xiaolin Li ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
High Photocatalytic Activity ◽  
Electrospinning Technique ◽  
Obvious Effect ◽  
Simple Method ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Excellent Photocatalytic Activity

Titanium dioxide (TiO2) nanofibers in the anatase structure were successfully prepared via electrospinning technique followed by calcination process. The morphologies, crystal structure, surface area, and the photocatalytic activity of resulting TiO2nanofibers were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen sorption, and UV-vis spectroscopy. The results revealed that calcination temperature had greatly influenced the morphologies of TiO2nanofibers, but no obvious effect was noticed on the crystal structure of TiO2nanofibers. The photocatalytic properties of TiO2nanofibers were evaluated by photocatalytic degradation of rhodamine B (RhB) in water under visible light irradiation. It was observed that TiO2nanofibers obtained by calcination at 500°C for 3 hours exhibited the most excellent photocatalytic activity. We present a novel and simple method to fabricate TiO2nanofibers with high-photocatalytic activity.

Synthesis and upconversion luminescence properties of CaF2:Yb3+,Er3+ nanoparticles obtained from SBA-15 template

2010 ◽  
Vol 25 (10) ◽  
pp. 2035-2041 ◽  
Author(s):  
Zhiguo Xia ◽  
Peng Du
Keyword(s):  
Electron Microscopy ◽  
Upconversion Luminescence ◽  
Emission Spectra ◽  
Average Diameter ◽  
Cubic Phase ◽  
Pumping Power ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Transmission Electron

CaF2:Yb3+,Er3+ upconversion (UC) luminescence nanoparticles have been synthesized using mesoporous silica (SBA-15) as a hard template. The samples were characterized by x-ray diffraction, Fourier transform infrared spectra, field-emission scanning electron microscopy, transmission electron microscopy, and UC emission spectra, respectively. Highly crystalline cubic phase CaF2:Yb3+,Er3+ nanoparticles are uniformly distributed with an average diameter of about 40–50 nm, and the formation process is also demonstrated. The UC fluorescence has been realized in the as-prepared CaF2:Yb3+,Er3+ nanoparticles on 980-nm excitation. The UC emission transitions for 4F9/2–4I15/2 (red), 2H11/2–4I15/2 (green), 4S3/2–4I15/2 (green), and 2H9/2–4I15/2 (violet) in the Yb3+/Er3+ codoped CaF2 nanoparticles depending on pumping power and temperature have been discussed. The UC mechanism, especially the origin on the temperature-dependent UC emission intensities ratio between 2H11/2 and 4S3/2 levels, have been proposed.

An environmentally friendly method for the isolation of cellulose nano fibrils from banana rachis fibers

2016 ◽  
Vol 87 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Vincent Mukwaya ◽  
Weidong Yu ◽  
Rabie AM Asad ◽  
Hajo Yagoub
Keyword(s):  
Electron Microscopy ◽  
Average Diameter ◽  
Enzyme Hydrolysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sonic Treatment ◽  
Xrd Studies ◽  
Environmentally Friendly Method ◽  
Derivative Thermogravimetry

Cellulose nano fibrils (CNFs) were isolated from banana rachis bran using enzyme hydrolysis with subsequent ultra-sonic treatment. The CNFs and bran were characterized by particle size distribution (only the CNFs), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy; the morphology of the banana rachis fiber and CNFs was observed using scanning electron microscopy and transmission electron microscopy, respectively. The furnished nano fibrils had an average diameter of 14.02 ± 2.10 nm and length of 619.6 ± 90.7 nm. The aspect ratio of the CNFs is in the range of long fibrils, that is 44.18. XRD studies revealed that CNFs (48.83%) were more crystalline than the banana bran (27.76%). TGA and derivative thermogravimetry thermograms showed that CNFs were more thermally stable than the bran.

Hydrothermal Synthesis and Photocatalytic Properties of Flower-Like CdS Nanostructures

2011 ◽  
Vol 335-336 ◽  
pp. 460-463 ◽  
Author(s):  
Hong Mei Wang ◽  
Da Peng Zhou ◽  
Yuan Lian ◽  
Ming Pang ◽  
Dan Liu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Sulfur Source ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Transmission Electron ◽  
Cds Nanostructures

Hexagonal flower-like CdS nanostructures were successfully synthesized through a facile hydrothermal method with thiourea as sulfur source. By combining the results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), the structural and morphological characterizations of the products were performed. The photocatalytic activity of CdS nanostructures had been tested by degradation of Rhodamine B (RB) under UV light compared to commercial CdS powders, which indicated that the as-syntherized CdS nanostructures exhibited enhanced photocatalytic activity for degradation of RB. The possible growth mechanism of CdS nanostructures was proposed in the end.

Hydrothermal Synthesis and Photocatalytic Properties of TiO2/SnS2 Nanocomposite

2014 ◽  
Vol 898 ◽  
pp. 23-26
Author(s):  
Jing Li ◽  
Wei Sun ◽  
Wei Min Dai ◽  
Yong Cai Zhang
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance ◽  
Photocatalytic Property ◽  
Deionized Water ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Chloride Pentahydrate

TiO2/SnS2 nanocomposite was synthesized via hydrothermal treatment of tin (IV) chloride pentahydrate, thioacetamide and TiO2 nanotubes in deionized water at 150 °C for 3 h. The structure, composition and optical property of the as-synthesized nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and UV-vis diffuse reflectance spectra, and its photocatalytic property was tested in the reduction of aqueous Cr6+ under visible-light (λ > 420 nm) irradiation. It was observed that TiO2 nanotubes exhibited no photocatalytic activity, whereas TiO2/SnS2 nanocomposite exhibited photocatalytic activity in the reduction of aqueous Cr6+ under visible-light (λ > 420 nm) irradiation.

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