The Effects of Temperature of Hydrothermal Growth of Titanium Dioxide Nanomaterial

2012 ◽  
Vol 545 ◽  
pp. 93-99
Author(s):  
Ahmad Anis Kalantar Mastan ◽  
Muti Mohamed Norani ◽  
Sharizal Shaik Ahmedullah
Keyword(s):  
Electron Microscopy ◽  
Titanium Dioxide ◽  
Surface Morphology ◽  
Sodium Hydroxide Solution ◽  
Hydrothermal Growth ◽  
X Ray Diffraction ◽  
Average Width ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm

Titanium dioxide (titania) nanomaterials have been extensively studied for various applications including gas sensor [1], dye-sensitized solar cell [2] and photocatalyst [3]. Titania nanomaterials can be produced using various methods depending on the desired surface morphology. As such the optimization of methods is the key to produce nanomaterials with desired properties where the study here focuses on the effect of autoclaving temperature for the hydrothermal growth. Titania P25 (Degussa, Germany) in 5 M sodium hydroxide solution (NaOH) was treated hydrothermally for 24 hours at 100 °C, 120 °C, 150 °C and 170 °C. Hydrothermal treatment for 24 hours at 150 °C produced nanotubes and treatment at 170 °C produces nanowires. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) were performed to study the surface and internal morphology of nanomaterials formed. Nanowires produced are of average width of 20 nm and length of 200 nm to 1 µm. Nanotubes produced are average width of 25 nm consisting of multiple walls. Varying the autoclaving temperature will affect the surface morphology of nanomaterials; forming nanotubes at 150 °C and nanowires at 170 °C. Understanding the effect of the process temperature would allow for optimization of the process in order to produce titania nanomaterial with specific characteristics that exhibit enhanced functionality for the development of their applications.

scholarly journals Synthesis, Structure, and Luminescent Properties of Europium-Doped Hydroxyapatite Nanocrystalline Powders

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Carmen Steluta Ciobanu ◽  
Simona Liliana Iconaru ◽  
Florian Massuyeau ◽  
Liliana Violeta Constantin ◽  
Adrian Costescu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Textural Properties ◽  
Average Crystallite Size ◽  
Luminescent Properties ◽  
Nanocrystalline Powders ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vibrational Studies ◽  
20 Nm

The luminescent europium-doped hydroxyapatite (Eu:HAp, Ca10−xEux(PO4)6(OH)2) with0≤x≤0.2nanocrystalline powders was synthesized by coprecipitation. The structural, morphological, and textural properties were well characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The vibrational studies were performed by Fourier transform infrared, Raman, and photoluminescence spectroscopies. The X-ray diffraction analysis revealed that hydroxyapatite is the unique crystalline constituent of all the samples, indicating that Eu has been successfully inserted into the HAp lattice. Eu doping inhibits HAp crystallization, leading to a decrease of the average crystallite size from around 20 nm in the undoped sample to around 7 nm in the sample with the highest Eu concentration. Furthermore, the samples show the characteristic5D0→7F0transition observed at 578 nm related to Eu3+ions distributed on Ca2+sites of the apatitic structure.

scholarly journals Application of Titanium Dioxide-Graphene Composite Material for Photocatalytic Degradation of Alkylphenols

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Chanbasha Basheer
Keyword(s):  
Electron Microscopy ◽  
Titanium Dioxide ◽  
Photocatalytic Efficiency ◽  
Ionization Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Flame Ionization ◽  
Transmission Electron ◽  
Wastewater Samples

Titanium dioxide-graphene (TiO2-G) composite was used for the photodegradation of alkylphenols in wastewater samples. The TiO2-G composites were prepared via sonochemical and calcination methods. The synthesized composite was characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), and fluorescence spectroscopy. The photocatalytic efficiency was evaluated by studying the degradation profiles of alkylphenols using gas chromatography-flame ionization detector (GC-FID). It was found that the synthesized TiO2-G composites exhibit enhanced photocatalytic efficiencies as compared to pristine TiO2. The presence of graphene not only provides a large surface area support for the TiO2photocatalyst, but also stabilizes charge separation by trapping electrons transferred from TiO2, thereby hindering charge transfer and enhancing its photocatalytic efficiency.

Nanoporous Ni and Ni-Cu Fabricated by Dealloying

2009 ◽  
Vol 1228 ◽  
Author(s):  
Masataka Hakamada ◽  
Yasumasa Chino ◽  
Mamoru Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Noble Metals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Difference ◽  
20 Nm ◽  
Good Workability ◽  
Scanning Electron

AbstractMetallic nanoporous architecture can be spontaneously attained by dealloying of a binary alloy. The nanoporous architecture can be often fabricated in noble metals such as Au and Pt. In this study, nanoporous Ni, Ni-Cu are fabricated by dealloying rolled Ni-Mn and Cu-Ni-Mn alloys, respectively. Unlike conventional Raney nickel composed of brittle Ni-Al or Cu-Al intermetallic compounds, the initial alloys had good workability probably because of their fcc crystal structures. After the electrolysis of the alloys in (NH4)2SO4 aqueous solution, nanoporous architectures of Ni and Ni-Cu with pore and ligament sizes of 10–20 nm were confirmed by scanning electron microscopy and transmission electron microscopy. X-ray diffraction analyses suggested that Ni and Cu atoms form a homogeneous solid solution in the Ni-Cu nanoporous architecture. The ligament sizes of nanoporous Ni and Ni-Cu were smaller than that of nanoporous Cu, reflecting the difference between diffusivities of Ni and Cu at solid/electrolyte interface. Ni can reduce the pore and ligament sizes of resulting nanoporous architecture when added to initial Cu-Mn alloys.

Optical and photocatalytic properties of photoactive paper with polycrystalline TiO2 nanopigment for optimal product design

TAPPI Journal ◽  
2012 ◽  
Vol 11 (5) ◽  
pp. 33-38 ◽  
Author(s):  
SEONGHYUK KO ◽  
PAUL D. FLEMING ◽  
MARGARET JOYCE ◽  
PNINA ARI-GUR
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gas Chromatography ◽  
Titanium Dioxide ◽  
Optical Properties ◽  
Photocatalytic Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Optimal Product Design

We investigated the effect of the crystalline phases of titanium dioxide nanopigment to optimize the optical properties and photocatalytic activity for synthesizing a photoactive paper. Six different ratios of anatase to rutile were prepared. Phase change and particle size were characterized using X-ray diffraction and transmission electron microscopy. Optical properties including opacity and brightness were tested. Photocatalytic activity was evaluated by measuring toluene decomposition, using gas chromatography. A specific ratio between two different crystallites of titanium dioxide showed relatively better optical and photoactive properties. The optimal anatase-to-rutile ratio was found to be 0.52:0.48.

scholarly journals Microstructure and Oxidation Behavior of Metal V Films Deposited by Magnetron Sputtering

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 425 ◽  
Author(s):  
Song Zhang ◽  
Tingting Wang ◽  
Ziyu Zhang ◽  
Jun Li ◽  
Rong Tu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Oxidation Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Force ◽  
Transmission Electron ◽  
Influence Of Substrate

Direct-current magnetron sputtering (DCMS) was applied to prepare vanadium (V) films on Si substrate. The influence of substrate temperature (Ts) and target–substrate distance (Dt–s) on phase structure and surface morphology of V films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscope (AFM) and transmission electron microscopy (TEM). The results show that the crystallinity of the V films increases with increasing Ts and decreasing Dt–s. The film deposited at Ts = 400 °C and Dt–s = 60 mm exhibits the best crystallinity and <111> preferred orientation with a regular tetrahedral surface morphology. Oxidation behavior of the V thin films has also been studied by X-ray photoelectron spectroscopy (XPS).

Microstructure of Ti6Al4V after Ultrasound-Aided Deep Rolling

2013 ◽  
Vol 661 ◽  
pp. 141-144
Author(s):  
Li Li ◽  
Zhen Yu Fu ◽  
Tao Li ◽  
Jin Jun Liu ◽  
Zheng Yu Tian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Microstructure ◽  
Deep Rolling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ti6al4v Titanium Alloy ◽  
Transmission Electron ◽  
20 Nm ◽  
Scanning Electron

Ti6Al4V titanium alloy was treated by an ultrasound-aided deep rolling (UADR) process. The microstructure of UADR treated specimen was observed via using scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Results show that ultrasound-aided deep rolling produced nanocrystallized microstructure of grain scale typically less than 20 nm on the immediate surface of Ti6Al4V. A nanometer to submicron gradient structured layer penetrating to a depth of about 150 μm was formed after UADR treatment. The above improvements of surface microstructure of the UADR treated specimen is believed to be beneficial to its anti-fatigue performance.

Nanostructured red-emitting MgGa2O4:Eu3+ phosphors

2004 ◽  
Vol 19 (5) ◽  
pp. 1504-1508 ◽  
Author(s):  
Bin-Siang Tsai ◽  
Yen-Hwei Chang ◽  
Yu-Chung Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sol Gel ◽  
Photoluminescence Intensity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Gel Technique ◽  
Red Luminescence ◽  
20 Nm

Nano-grained phosphors of Eu3+-doped MgGa2O4 crystallites were prepared by sol-gel technique. The characterization and optical properties of luminescent MgGa2O4:Eu3+ powders have been investigated. The dried sol-gel powders were calcined in air at different temperature from 600 to 1000 °C for 5 h. The x-ray diffraction profiles showed that the MgGa2O4:Eu3+ powders began to crystallize around 600 °C and formed stable MgGa2O4 phase in the temperature range of 600–900 °C. The transmission electron microscopy morphology observations revealed that the fired powders exhibit small grain size less than 20 nm. In the PL studies, under ultraviolet (394 nm) excitation, the calcined powders emitted bright red luminescence (615 nm, 5D0→7F2), and the powders fired at 900 °C were found to have the maximum photoluminescence intensity. The quenching concentration of Eu3+ in MgGa2O4 crystallites was also indicated to be about 5∼6 mol%.

Controlled Synthesis of Hierarchical Flower-Like CuS Spheres by a Facile Microwave Hydrothermal Method

2012 ◽  
Vol 512-515 ◽  
pp. 265-268 ◽  
Author(s):  
Hui Qi ◽  
Jian Feng Huang ◽  
Li Yun Cao ◽  
Jian Peng Wu
Keyword(s):  
Electron Microscopy ◽  
Cetyltrimethylammonium Bromide ◽  
Controlled Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Hydrothermal ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Average Size ◽  
20 Nm

–Hierarchical flower–like CuS spheres have been synthesized by a facile microwave hydrothermal (MH) method using cetyltrimethylammonium bromide (CTAB) as the surfactant. The as–prepared CuS crystallites under different CTAB contents were characterized by X–ray diffraction (XRD), field–emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). Results show that the CTAB–assisted CuS particles have hierarchical flower–like microstructures that were assembled by thin nanoflakes with thickness of 10~20 nm. The corresponding HRTEM images reveal that these nanoflakes are composed of many nanoparticles with average size of about 7 nm. Moreover, when increasing the CTAB contents from 0 g⁄mL to 0.02 g⁄mL, the as–prepared CuS particles were found to have better dispersion stability with decreased average sizes of the hierarchical flower–like spheres. Comparing with the bulk CuS particles, the related UV–vis absorption spectrum of the as–prepared crystallites exhibits an obvious red shift with the absorption peak at 739 nm.

scholarly journals Synthesis of an optical catalyst for cracking contaminating dyes in the wastewater of factories using indium oxide in nanometer and usage in agriculture

2019 ◽  
Vol 21 (4) ◽  
pp. 98-105 ◽  
Author(s):  
Ishaq F. E. Ahmed ◽  
Ahmed I. El-Shenawy ◽  
Moamen S. Refat
Keyword(s):  
Electron Microscopy ◽  
Indium Oxide ◽  
Organic Dyes ◽  
Low Cost ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
20 Nm

Abstract Herein, the photocatalytic degradation of the Congo Red (CR) and Crystal Violet (CV) dyes in an aqueous solution were discussed in the presence of an indium(III) oxide (In2O3) as optical catalyst efficiency. The caproate bidentate indium(III) precursor complex has been synthesized and well interpreted by elemental analysis, molar conductivity, Fourier transform infrared (FT-IR), UV-Vis, and thermogravimetric (TGA) with its differential thermogravimetric (DTG) studies. The microanalytical and spectroscopic assignments suggested that the associated of mononuclear complex with 1:3 molar ratio (M3+:ligand). Octahedral structure is speculated for this parent complex of the caproate anion, CH3(CH2)4COO− ligand. The In2O3 NPs with nanoscale range within 10–20 nm was synthesized by a simple, low cost and eco-friendly method using indium(III) caproate complex. Indium oxide nanoparticles were formed after calcination of precursor in static air at 600°C for 3 hrs. The structural, grain size, morphological and decolorization efficiency of the synthesized NPs were characterized using the FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM) analyses. It was worthy mentioned that the prepared In2O3 NPs showed a good photodegradation properties against CR and CV organic dyes during 90 min.

Effects of pressure on the solidification of Al–Mn alloy

2001 ◽  
Vol 16 (4) ◽  
pp. 910-913 ◽  
Author(s):  
Duanwei He ◽  
M. He ◽  
C. S. Kiminami ◽  
F. X. Zhang ◽  
Y. F. Xu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Evolution ◽  
X Ray Diffraction ◽  
Thermodynamic Variable ◽  
X Ray ◽  
Lattice Constants ◽  
Transmission Electron ◽  
20 Nm ◽  
New Phase ◽  
C Center

The solidification of Al–20 wt% Mn alloy was investigated under pressures up to 6 GPa. It was found that the solidification products under pressures below 4 Gpa were about the same, composed mainly of Al and Al6Mn. A new Al–Mn phase with needle like morphology and Al nanocrystallites in size less than 20 nm were obtained in the quenched alloy at 6 GPa. Structure analysis by transmission electron microscopy and x-ray diffraction indicated that the new phase had a C-center othorhombic unit cell with lattice constants of a = 0.7565(4) nm, b = 1.2965(6) nm, and c = 0.7801(6) nm. The composition was determined to be Al77.5Mn22.5 by election probe microanalysis. The phase evolution during solidification under different pressures was discussed. Our experimental results show that the pressure, as a basic thermodynamic variable like temperature, may play an important role on the solidification of the alloy.

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