CeO2/TiO2 Nanotubes Composites: Synthesis, Characterization, and Photocatalytic Properties

2012 ◽  
Vol 583 ◽  
pp. 86-90 ◽  
Author(s):  
Hai Bin Li ◽  
Xin Yong Li ◽  
Yan De Song ◽  
Shu Guang Chen ◽  
Ying Wang ◽  
...  

TiO2nanotubes were prepared via a hydrothermal route. CeO2nanoparticles with diameters around 5nm were loaded onto the surface of TiO2nanotubes via a deposition approach followed by a calcination process. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-vis diffuse reflectance spectroscopy (UV-vis) were applied for the characterization of the as-prepared CeO2/TiO2nanotubes composites. The results show that CeO2particles are highly dispersed on the surface of TiO2nanotubes. The TiO2 nanotubes are modified to response to the visible light due to the combination with CeO2. The CeO2/TiO2nanotubes composites with a CeO2/TiO2atomic ratio of 2.5% show a further improvement on the photocatalytic activity for degradation of Rhodamine B in water. The presence of CeO2improves the light absorption of TiO2nanotubes and inhibits the electron-hole recombination.

2021 ◽  
Vol 12 (6) ◽  
pp. 7147-7158

This paper reports the structural, morphological, and antibacterial studies of ZrO2:Tb3+ nanophosphors (NPs). The ZrO2:Tb3+ NPs were synthesized by hydrothermal route using Amylamine as surfactant. ZrO2:Tb3+ nanophosphors was characterized by Powder X-ray Diffraction(PXRD), Scanning Electron Microscope (SEM),Diffuse reflectance spectroscopy (DRS), Photoluminescence(PL), Raman spectra, Fourier Transform Infrared radiation(FTIR) and Transmission Electron Microscope(TEM). PXRD analysis shows better crystallinity, cubic in-phase and good homogeneity of the synthesized phosphors were confirmed. When the Tb3+ concentration varies, we obtain blue emissions from ZrO2:Tb3+ NPs. ZrO2:Tb3+ NPs have a promising approach to blue light sources in the display application. SEM images show that ZrO2:Tb3+ nanophosphors have good morphology with a nonporous structure. TEM and SAED pattern confirms that ZrO2:Tb3+ nanophosphors are crystalline in nature. ZrO2:Tb3+ (9mol %) nanophosphors possessed a good antibacterial ability.


2018 ◽  
Vol 32 (17) ◽  
pp. 1850185 ◽  
Author(s):  
Yun-Hui Si ◽  
Yu Xia ◽  
Ya-Yun Li ◽  
Shao-Ke Shang ◽  
Xin-Bo Xiong ◽  
...  

A series of BiFeO3 and BiFe[Formula: see text]Mn[Formula: see text]O3 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by a hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS) and UV–Vis diffuse reflectance spectroscopy, and their photocatalytic activity was studied by photocatalytic degradation of methylene blue in aqueous solution under visible light irradiation. The band gap of BiFeO3 was significantly decreased from 2.26 eV to 1.90 eV with the doping of Mn. Furthermore, the 6% Mn-doped BiFeO3 photocatalyst exhibited the best activity with a degradation rate of 94% after irradiation for 100 min. The enhanced photocatalytic activity with Mn doping could be attributed to the enhanced optical absorption, increment of surface reactive sites and reduction of electron–hole recombination. Our results may be conducive to design more efficient photocatalysts responsive to visible light among narrow band gap semiconductors.


2016 ◽  
Vol 35 (6) ◽  
pp. 559-566 ◽  
Author(s):  
Elaheh Esmaeili ◽  
Mohammad Sabet ◽  
Masoud Salavati-Niasari ◽  
Kamal Saberyan

AbstractPbS nanostructures were synthesized successfully via hydrothermal approach with a new precursor. The products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV–Vis diffuse reflectance spectroscopy (DRS). The effect of different sulfur sources were investigated on product size and morphology.


2009 ◽  
Vol 79-82 ◽  
pp. 581-584 ◽  
Author(s):  
Li Ang Song ◽  
Li Xin Cao ◽  
Ge Su ◽  
Wei Liu ◽  
Hui Liu ◽  
...  

Titanium based nanotubes (8-12nm outer diameter and 4-6nm inner diameter) were successfully fabricated by a simple and cost-effective hydrothermal method. The nanotube-like amorphous phases TNT(Na) and TNT(H) were obtained with different post treatment. The samples were characterized by means of high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), selected area electron diffraction (SAED), energy dispersive X-ray spectrum (EDS) and UV-Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activities of the nanotubes were evaluated using photo-oxidation of methyl orange.


2010 ◽  
Vol 657 ◽  
pp. 62-74 ◽  
Author(s):  
Rajesh J. Tayade ◽  
D.L. Key

TiO2 derived nanotubes were prepared by hydrothermal treatment of TiO2 (anatase) powder in 10 M NaOH aqueous solution. The crystalline structure, band gap, and morphology of the TiO2 nanotubes were determined by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Transmission Electron microscopy (TEM) and N2 adsorption (BET) at 77 K, respectively. It was observed that the surface area of the nanotubes was increased twelve times compared with TiO2 (anatase) powder. The results demonstrated that the photocatalytic activity of TiO2 nanotubes was higher than that of TiO2 (anatase) powder. The photocatalytic activity of the nanotubes was evaluated in presence of sunlight by degradation of aqueous nitrobenzene. Complete degradation of nitrobenzene was obtained in 4 hours using TiO2 nanotubes whereas 85% degradation was observed in case of TiO2 (anatase).


2011 ◽  
Vol 239-242 ◽  
pp. 2323-2326 ◽  
Author(s):  
Hai Bin Li ◽  
Shu Guang Chen ◽  
Wei Ming Lu ◽  
Qi Cheng Liu

Mesoporous TiO2 microspheres with a combination of large surface and high crystallinity were fabricated by an ultrasonic-hydrothermal method with Octadecylamine as a structure-directing agent and tetrabutyl titanate as a precursor. The mesoporous materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption–desorption measurements, and UV–visible diffuse reflectance spectroscopy (UV-vis). Low-angle XRD and TEM images indicated that the disordered wormhole-like mesoporous architecture of TiO2 microspheres with diameters of about 200-400 nm were actually formed by agglomerization of nanoparticles with an average size of about 10nm. The analysis from N2 adsorption–desorption isotherms showed that the surface area of mesoporous sample was 204.7 m2g-1, with a pore size of 4.3 nm and pore volume of 0.263 cm3g-1 after calcined at 673 K.


2013 ◽  
Vol 652-654 ◽  
pp. 241-244
Author(s):  
Hai Bin Li ◽  
Yan De Song ◽  
Shu Guang Chen

CuO nanosheets in rectangle shape with widths around 90 nm and lengths about 180 nm were prepared via a hydrothermal route in the presence of CTAB. MnO2 nanoparticles with diameters around 10nm were loaded onto the surface of CuO nanosheets via an immersion approach followed by a calcination process. X-ray diffraction (XRD), Transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were applied for the characterization of the as-prepared MnO2 loaded CuO nanosheets. It was found that CTAB played a crucial role in the morphology-controlled synthesis of CuO nanosheets. The hindrance effect resulted from the preferred adsorption of CTAB on certain facets leading to the formation of CuO nanosheets. MnO2 loaded CuO nanosheets can be expected to be a promising catalyst for the heterogeneous catalytic ozonation due to its composite phases, high dispersity, and large specific surface area.


2008 ◽  
Vol 8 (6) ◽  
pp. 2983-2989 ◽  
Author(s):  
F. Paraguay-Delgado ◽  
R. Huirache-Acuña ◽  
M. Jose-Yacaman ◽  
G. Alonso-Nuñez

In this work, we report the synthesis and characterization of Mo-Ni-W oxides. The precursor was prepared from an aqueous solution of ammonium heptamolibdate, ammonium metatungstate, and nickel nitrate with an atomic ratio of 1:1:1 (Mo:W:Ni). The solution was then transferred to a Teflon-lined stainless steel autoclave and heated to 200 °C and left at this temperature for 48 h. The resulting material was then washed and dried. The morphology and elemental composition were studied by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The porosity was studied by the Brunauer, Emmett, and Teller method. The materials synthesized at 200 °C remained amorphous and had a specific surface area of 114 m2/g with pore size of 34 Å. The average length was 1 μm and the average diameter was 60 nm. The crystalline phase of synthesized material corresponded to W0.4Mo0.6O3 and WO3. After annealing at 550 °C for two hours, the material was polycrystalline with a segregated structure of MoO3, WO3; NiMoO4 was observed. The sublimation of the molybdenum oxide was evident when annealed at 900 °C for two hours and finally two crystalline phases of material remained; roundish WO3 and elongated particles of NiWO4.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.


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