The Photocatalysis Properties of Heterostructured WO3-TiO2 Composite Prepared by Waste WC-TiC Hardmetal

2013 ◽  
Vol 873 ◽  
pp. 603-611
Author(s):  
Yi Long Yang ◽  
Jin Shu Wang ◽  
Yong Li Li ◽  
Jun Shu Wu ◽  
Hong Yi Li
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Critical Role ◽  
Nitrogen Adsorption ◽  
Light Illumination ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Vis Spectroscopy ◽  
Adsorption Desorption

We reported a facile hydrothermal route for the preparation of WO3TiO2 composite nanoparticles (TWCNs) using waste WC-TiC hardmetal in the presence of hydrofluoric acid (HF). Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and nitrogen adsorption/desorption analysis were employed for structural and composition analyses of the TWCNs. Our results suggested that HF was not only strongly involved in the growth of WO3, but also played a critical role in the etching effect for TWCN product. The photocatalytic activity of TWCNs was investigated by UV-vis spectroscopy. Dye molecules could be rapidly decomposed with TWCNs photocatalyst under visible light illumination. The enhanced photocatalytic activity is attributed to well matched band edge positions of WO3 and TiO2, and the large specific surface area of TWCNs in view of the incorporation of mesopores. The results presented here are expected to make a contribution toward the development of recycling waste resource delicately for photocatalytic water purification.

scholarly journals Sonochemical Synthesis, Characterization, and Photocatalytic Activity of N-Doped TiO2Nanocrystals with Mesoporous Structure

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Tiekun Jia ◽  
Fang Fu ◽  
Junwei Zhao ◽  
Jian Chen ◽  
Xiaofeng Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Region ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Diffuse Reflection Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Average Size ◽  
Adsorption Desorption

N-Doped TiO2nanocrystals were synthesized via a simple sonochemical route, using titanium tetrachloride, aqueous ammonia, and urea as starting materials. The as-synthesized samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) equipped with an energy dispersion X-ray spectrometer (EDS), transmission electron microscopy (TEM), UV-vis diffuse reflection spectroscopy, Raman spectroscopy, and nitrogen adsorption-desorption isotherms. The results of TEM and nitrogen adsorption-desorption showed that the average size and specific surface area of the as-synthesized nanocrystals are 10 nm and 107.2 m2/g, respectively. Raman spectral characterization combined with the results of XRD and EDS revealed that N dopant ions were successfully doped into TiO2. Compared with pure TiO2, the adsorption band edge of N-doped TiO2samples exhibited an obvious red shift to visible region. The photocatalytic activities were evaluated by the degradation of Rhodamine B (RhB) under visible light, and the results showed that the N-doped TiO2sample synthesized by an optimal amount of urea exhibited excellent photocatalytic activity due to its special mesoporous structure and the incorporation of nitrogen dopant ions.

Synthesis of Flower-Like Mesoporous γ-AlOOH and γ-Al2O3 Nanoarchitectures via an Ionic Liquid-Assisted Hydrothermal Route

NANO ◽  
2019 ◽  
Vol 14 (04) ◽  
pp. 1950046
Author(s):  
Tong Il Kim ◽  
Hak Sung Yun ◽  
Yung Jon ◽  
Gwang Bok Han ◽  
Sung Il Chae ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Hydrothermal Reaction ◽  
Hydrothermal Process ◽  
Reaction System ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Adsorption Desorption

In this work, flower-like [Formula: see text]-AlOOH and [Formula: see text]-Al2O3 nanoarchitectures with excellent surface and mesoporous properties were successfully synthesized in ionic liquid-assisted hydrothermal reaction system. The as-prepared suprastructures were characterized by several techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption/desorption measurement. The formation mechanism of flower-like [Formula: see text]-AlOOH mesoporous crystallites by ionic liquid-assisted hydrothermal process was proposed and discussed. Flower-like [Formula: see text]-Al2O3 nanostructures were obtained by calcining the as-prepared [Formula: see text]-AlOOH at 600∘C for 2[Formula: see text]h, preserving the same morphology.

PEG-Assisted Hydrothermal Synthesis and Photocatalytic Activity of Bi2Fe4O9 Crystallites

2011 ◽  
Vol 1292 ◽  
Author(s):  
Dengrong Cai ◽  
Jianmin Li ◽  
Shundong Bu ◽  
Shengwen Yu ◽  
Dengren Jin ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectrum ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Peg 400 ◽  
Transmission Electron ◽  
Light Region ◽  
Facile Hydrothermal Route ◽  
Degradation Ratio

ABSTRACTA facile hydrothermal route assisted by polyethylene glycol (PEG) 400 was utilized to synthesize single-phase Bi2Fe4O9 crystallites. X-ray diffraction results showed the products with PEG 400 of 30 g/L exhibited a preferred growth along the (001) plane. Transmission electron microscopy indicated that the morphology of the as-prepared Bi2Fe4O9 crystallites with PEG 400 were plake-like and rod-like. Strong absorption in visible-light region of the products was characterized by UV-vis diffuse reflectance spectrum (UV-DRS). The photocatalytic activity of Bi2Fe4O9 crystallites was evaluated on degradation of methyl orange (MO) under visible light irradiation. For 3 h irradiation, the degradation ratio was increased to 93% with the aid of a small amount of H2O2. The analysis of FT-IR spectra proved that the Bi2Fe4O9 catalysts were remained stable after the photocalytic reactions.

Effect of hydrothermal dwell time on the diameter-controlled synthesis and magnetic property of MnO2 nanorods

2014 ◽  
Vol 28 (06) ◽  
pp. 1450045 ◽  
Author(s):  
Arbab Mohammad Toufiq ◽  
Fengping Wang ◽  
Qurat-ul-Ain Javed ◽  
Yan Li
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Dwell Time ◽  
Hydrothermal Reaction ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Hydrothermal Reaction Time

In this paper, single crystalline 1D tetragonal MnO 2 pen-type nanorods were synthesized by varying the dwell time through a facile hydrothermal route at a reaction temperature of 250°C. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies showed that the diameter of MnO 2 nanorods decreases from 460 nm to 250 nm with the increase in hydrothermal reaction time from 5 h to 15 h. Field-emission scanning electron microscopy (FESEM) and TEM studies revealed the evolution of improved surface morphology of MnO 2 nanorods that are prepared with longer hydrothermal reaction time. The magnetic properties of the products were evaluated using vibrating sample magnetometer (VSM) at room temperature, which showed that the as-prepared samples exhibit weak ferromagnetic behavior. The effect of diameter on the magnetization values was observed and discussed in detail.

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.

scholarly journals Synthesis of V2O3/C composites with different morphologies by a facile route and phase transition properties of the compounds

2014 ◽  
Vol 32 (2) ◽  
pp. 236-242 ◽  
Author(s):  
Yifu Zhang ◽  
Nannan Wang ◽  
Yuting Huang ◽  
Chi Huang ◽  
Xiao Mei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Hydrothermal Route ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Potential Applications ◽  
Subsequent Calcination ◽  
Ft Ir ◽  
First Time

AbstractV2O3 and amorphous carbon composites (V2O3/C composites) with different morphologies (e.g. nanospheres, nanorods and nanosheets) were, for the first time, successfully synthesized by a facile hydrothermal route and subsequent calcination. The as-obtained samples were characterized by X-ray powder diffraction (XRD), energy dispersive spectrometery (EDS), elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The morphology of V2O3/C composites could be easily controlled by varying the reaction time, and, as a result, V2O3/C composites with nanospheres, nanorods and nanosheets were selectively synthesized. Furthermore, the phase transition property of V2O3/C composites was measured by differential scanning calorimetry (DSC), suggesting that V2O3/C composites exhibit the phase transition similar to V2O3, which could expand the potential applications of materials related to V2O3 in the future.

SYNTHESIS, CHARACTERIZATION AND THE APPLICABILITY OF β-CYCLODEXTRINS FUNCTIONALIZED MESOPOROUS SBA-15 MOLECULAR SIEVES

NANO ◽  
2013 ◽  
Vol 08 (05) ◽  
pp. 1350050
Author(s):  
MIN GUAN ◽  
HAI-PENG BI ◽  
ZUYUAN WANG ◽  
SHAOHUA BU ◽  
LING HUANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Molecular Sieves ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Capacities ◽  
Transmission Electron ◽  
Potential Applications ◽  
Adsorption Desorption

Mesoporous silicas SBA-15 are modified with β-Cyclodextrins (β-CD) by simple grafting method. β-CD functionalized SBA-15 was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), nitrogen adsorption–desorption measurements, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Furthermore, the applicability of it is investigated through studying the adsorption properties of clenbuterol. It showed better adsorption capacities of clenbuterol than pure SBA-15. β-CD functionalized SBA-15 material has the potential applications in the treatment of clenbuterol contamination in food and environment science.

scholarly journals Oxidative Coupling of Methane over Mn2O3-Na2WO4/SiC Catalysts

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 363
Author(s):  
Jieun Kim ◽  
La-Hee Park ◽  
Jeong-Myeong Ha ◽  
Eun Duck Park
Keyword(s):  
Electron Microscopy ◽  
High Temperatures ◽  
Oxidative Coupling ◽  
Exothermic Reaction ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Oxidative Coupling Of Methane ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Adsorption Desorption

The oxidative coupling of methane (OCM) is operated at high temperatures and is a highly exothermic reaction; thus, hotspots form on the catalyst surface during reaction unless the produced heat is removed. It is crucial to control the heat formed because surface hotspots can degrade catalytic performance. Herein, we report the preparation of Mn2O3-Na2WO4/SiC catalysts using SiC, which has high thermal conductivity and good stability at high temperatures, and the catalyst was applied to the OCM. Two Mn2O3-Na2WO4/SiC catalysts were prepared by wet-impregnation on SiC supports having different particle sizes. For comparison, the Mn2O3-Na2WO4/SiO2 catalyst was also prepared by the same method. The catalysts were analyzed by nitrogen adsorption–desorption, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The transformation of SiC into α-cristobalite was observed for the Mn2O3-Na2WO4/SiC catalysts. Because SiC was completely converted into α-cristobalite for the nano-sized SiC-supported Mn2O3-Na2WO4 catalyst, the catalytic performance for the OCM reaction of Mn2O3-Na2WO4/n-SiC was similar to that of Mn2O3-Na2WO4/SiO2. However, only the surface layer of SiC was transformed into α-cristobalite for the micro-sized SiC (m-SiC) in Mn2O3-Na2WO4/m-SiC, resulting in a SiC@α-cristobalite core–shell structure. The Mn2O3-Na2WO4/m-SiC showed higher methane conversion and C2+ yield at 800 and 850 °C than Mn2O3-Na2WO4/SiO2.

Facile Cetyltrimethylammonium Bromide (CTAB)-assisted Synthesis of Calcium Bismuthate Nanoflakes with Solar Light Photocatalytic Performance

2020 ◽  
Vol 16 ◽  
Author(s):  
Zi Wang ◽  
Hongjun Chen ◽  
Fanglv Qiu ◽  
Zeyang Xue ◽  
Chunhu Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Cetyltrimethylammonium Bromide ◽  
Photocatalytic Performance ◽  
Gentian Violet ◽  
Diffuse Reflectance Spectrum ◽  
Solar Light ◽  
Hydrothermal Route ◽  
Ctab Concentration ◽  
Transmission Electron

Background: Wastewater with dyes will pollute the environment and cause serious risk to human health and aquatic biota. Gentian violet (GV) belongs to typical triphenylmethane dyes and is difficult to be degraded. Calciumbismuthate nanoflakes possess good photocatalytic activity toward GV under solar lightirradiation. Objective: The aim is to prepare calcium bismuthate nanoflakes by the hydrothermal method and research the solar light photocatalytic performance of the calciumbismuthate nanoflakes for GV degradation. Methods: Calcium bismuthate nanoflakes were synthesized via a facile hydrothermal route assisted by cetyltrimethylammonium bromide(CTAB) based on the reaction of sodium bismuthate and calcium chloride. The calcium bismuthate products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy and solid UV-vis diffuse reflectance spectrum. Results: The calcium bismuthate nanoflakes possess single crystalline mono clinic CaBi2O4 phase. The size of the whole nanoflakes is about 10 μm and thickness of the nanoflakes is about 40 nm. The morphology, size and phase of the products are closely relative to CTAB concentration, reaction temperature and reaction time. The band gap of the calcium bismuthate nanoflakes is 2.21 eV. The photocatalytic activity of the calcium bismuthate nanoflakes is high enough to completely degrade GV under solar light irradiation for 6 h.

scholarly journals SYNTHESIS AND ELECTROCHEMICAL PROPERTIES OF MESOPOROUS CARBON SUPPORTED WELL–DISPERSED COBALT OXIDES NANOPARTICLES

2018 ◽  
Vol 55 (1B) ◽  
pp. 230
Author(s):  
Nguyen Van Tu
Keyword(s):  
Electron Microscopy ◽  
Cobalt Oxide ◽  
Mesoporous Carbon ◽  
Good Control ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Oxide Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Transmission Electron ◽  
Adsorption Desorption

In this article, well–dispersed cobalt oxide nanoparticles supported on mesoporous carbon (CMK–3) have been successfully synthesized. The composites were characterized by field emission scanning electron microscopy, transmission electron microscopy, X–ray diffraction and nitrogen adsorption–desorption analysis. The results have confirmed that, at a cobalt loading of 15 wt%, the composites have not only retained mesoporous structure of the support but also shown a good control of dispersed cobalt oxide nanoparticles with size of ~4 nm. The electrochemical property tests for the synthesized samples have shown significant improvement compared to the blank carbon (CMK–3) without cobalt oxide incorporation.

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