Tuning the bandgap in Co-doped Mg(OH)2 nanoparticles

2019 ◽  
Vol 33 (17) ◽  
pp. 1950182
Author(s):  
Syed Masood Raza ◽  
S. Rizwan Ali ◽  
M. Naeem ◽  
Zaheer Uddin ◽  
Sadaf Qaseem ◽  
...  
Keyword(s):  
Lattice Distortion ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
Sem Images ◽  
X Ray ◽  
Shaped Particle ◽  
Co Concentration ◽  
Co Doped ◽  
Scanning Electron

Cobalt (Co) doped magnesium hydroxide Mg(OH)2 nanoparticles are synthesized by a surfactant-free co-participation method. Scanning electron microscopy (SEM) images show nanometer size Mg(OH)2 particles in spherically shaped particle-like morphology. Synthesis of these Mg(OH)2 nanocrystals involves the formation of monomeric MgOH[Formula: see text] ions as the precursor for the Mg(OH)2 nuclei which finally evolves in spherical particle-like morphology. X-ray diffraction (XRD) confirms the hexagonal crystal structure of the samples. With increasing Co concentration, the absorption spectra of the samples show narrowing of the bandgap from 5.47 eV (for pure Mg(OH2)) to 5.26 eV (for 10% Co-doped Mg(OH2)) effect is attributed to changes in the interaction potentials between Co and the host Mg(OH)2 lattice due to dopant-induced lattice distortion and the presence of a mixed valance Co[Formula: see text]/Co[Formula: see text] state.

scholarly journals New Ternary Compounds of the Composition Cu2SnTi3 and Their Crystal Structures

2020 ◽  
Vol 10 (24) ◽  
pp. 8776
Author(s):  
Sheng-Fang Huang ◽  
Yen-Cheng Chang ◽  
Po-Liang Liu
Keyword(s):  
Crystal Structure ◽  
Total Energy ◽  
Ternary Compound ◽  
Density Functional ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
Orthorhombic Crystal Structure ◽  
X Ray ◽  
Atomic Structures

A new ternary compound Cu2SnTi3 has been synthesized by vacuum sintering at 900 °C. The atomic structures of CaCu5- and InNi2-like Cu2SnTi3 are calculated using density functional theory methods. The X-ray diffraction (XRD) analysis and selected area diffraction (SAD) patterns of the new ternary compound Cu2SnTi3 are considered to verify the atomic structures of CaCu5- and InNi2-like Cu2SnTi3. The results reveal that the InNi2-like Cu2SnTi3 model has the lowest total energy of −35.239 eV, representing the trigonal crystal structure. The orthorhombic crystal structure of the CaCu5-like Cu2SnTi3 model has the second lowest total energy of −33.926 eV. Our theoretical X-ray diffraction peak profiles of InNi2-like (CaCu5-like) Cu2SnTi3 are nearly identical to experimental one, leading to an error below 2.0% (3.0%). In addition, the hexagonal crystal structure of the CaCu5-like Cu2SnTi3 model has the highest total energy of −33.094 eV. The stability of the Cu2SnTi3 in terms of energy follows the order: the trigonal, orthorhombic, and hexagonal crystal structure.

Characterization of Zn0.96Al0.02Ga0.02O Thermoelectric Material

2013 ◽  
Vol 802 ◽  
pp. 227-231
Author(s):  
Panida Pilasuta ◽  
Pennapa Muthitamongkol ◽  
Chanchana Thanachayanont ◽  
Tosawat Seetawan
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Single Phase ◽  
Hexagonal Structure ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
X Ray ◽  
Transmission Electron

Crystal structure of Zn0.96Al0.02Ga0.02O was analyzed by X-Ray diffraction (XRD) technique and the microstructure was observed by scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The XRD results showed single phase and hexagonal structure a = b = 3.24982 Å, and c = 5.20661 Å. The SEM and TEM results showed the grain size of material arrangement changed after sintering and TEM diffraction pattern confirmed hexagonal crystal structure of Zn0.96Al0.02Ga0.02O after sintering.

Different Cr Contents in Nanostructured Fe-Ni-Cr Alloys Prepared by Mechanical Alloying

2012 ◽  
Vol 531-532 ◽  
pp. 437-441 ◽  
Author(s):  
Qi He ◽  
Tao Liu ◽  
Jian Liang Xie
Keyword(s):  
Particle Size ◽  
Mechanical Alloying ◽  
Ball Milling ◽  
Lattice Distortion ◽  
Milling Time ◽  
Nanocrystalline Powders ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ball Milling Time ◽  
Scanning Electron

Fe-Ni-Cr alloy powders with the different components were prepared by Mechanical Alloying (MA). The phase structure, grain size, micro-strain and lattice distortion were determined with X-ray diffraction. The morphology and particle size of the powders were observed and analyzed using a field emission scanning electron microscopy. The results showed that the Fe-Ni-Cr nanocrystalline powders could be obtained by MA. The ball milling time could be reduced with increasing amount of Cr, resulting the formation of Fe-Ni-Cr powders. With the increasing amount of Cr, the speed of Ni diffusion to Fe lattice approaching saturation became more rapid. The particle size got smaller as the ball milling went further; the extent of micro-strain and distortion of lattice intensified; the solid solubility of Ni and Cr in Fe was increased. Finally the super-saturated solid solution of Fe was obtained.

Catalytic crosslinking of a regenerated hydrophobic benzylated cellulose and nano TiO2 composite for enhanced oil absorbency

e-Polymers ◽  
2017 ◽  
Vol 17 (4) ◽  
pp. 295-302
Author(s):  
Oluwaseyi D. Saliu ◽  
Gabriel A. Olatunji ◽  
Azeh Yakubu ◽  
Mariam T. Arowona ◽  
Aminat A. Mohammed
Keyword(s):  
Aluminum Sulfate ◽  
Oil Absorption ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
Sem Images ◽  
X Ray ◽  
High Q ◽  
Stretching Vibrations ◽  
Emission Microscopy ◽  
Scanning Electron

AbstractHydrophobic cellulosic composites with the nano form of metal oxides possess good absorptive and adsorptive potentials. Native cellulose was regenerated, benzylated, crosslinked and blended with TiO2 nanoparticles to absorb toluene, xylene, chloroform, kerosene and petrol. The composite was fully characterized by scanning electron microscopy (SEM), transmission emission microscopy (TEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The effect of crosslinker, catalyst and time of absorption was investigated. The FTIR shows stretch and bend vibrations of hydroxyl (-OH), alkyl (-CH), aromatic double bond (C=C) for benzyl cellulose while the appearance of new peaks at 816, 769 and 726 cm−1 for Ti-O stretching vibrations confirms the successful synthesis of the composite. The SEM images revealed the transformation of foam-like appearance of benzyl cellulose to a solidified mass after TiO2 compositing. Enhanced oil absorption was seen as the amount of the aluminum sulfate catalyst was doubled as a high Qmax of 24.16, 25.81, 27.22, 24.03 and 24.43 was obtained when the amount of catalyst used was doubled.

scholarly journals An XRD, SEM and TG study of a uranopilite from Australia

2006 ◽  
Vol 70 (3) ◽  
pp. 299-307 ◽  
Author(s):  
R.L. Frost ◽  
M.L. Weier ◽  
G.A. Ayoko ◽  
W. Martens ◽  
J. Čejka
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Northern Territory ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Evolved Gas ◽  
X Ray ◽  
Temperature Range ◽  
Step Over ◽  
Scanning Electron

AbstractA uranopilite from The South Alligator River, Northern Territory, Australia, has been studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) with EDAX attachment, and thermogravimetry in conjunction with evolved gas mass spectrometry. The XRD shows that the mineral is a pure uranopilite with few if any impurities. The SEM images show that the uranopilite consists of elongated crystals, up to 50μm long and 5 μm wide. Thermogravimetry combined with mass spectrometry shows that dehydration occurs at ∼31°C resulting in the formation of metauranopilite. The first dehydration step over 20–71°C corresponds to a decrease of 5.4 wt.%, equivalent to 6.076 H2O. The second dehydration step, over the temperature range 71 –162.4°C corresponds to a decrease of 4.7 wt.%, equivalent to 5.288 H2O, making a total of 11.364 moles of H2O, close to 12 H2O for uranopilite.Dehydroxylation takes place over the temperature range 80–160°C. The loss of sulphate occurs at higher temperatures in two steps at 622 and 636°C. A mass loss also occurs at 755°C, accounted for by evolved oxygen.

Electrochemical synthesis and properties of layer-structured polypyrrole/montmorillonite nanocomposite films

2010 ◽  
Vol 25 (4) ◽  
pp. 658-664 ◽  
Author(s):  
Chang-An Wang ◽  
Keyu Chen ◽  
Yong Huang ◽  
Huirong Le
Keyword(s):  
Deposition Time ◽  
Composite Films ◽  
Nanocomposite Films ◽  
Nanoindentation Test ◽  
Test Results ◽  
X Ray Diffraction ◽  
Free Standing ◽  
Sem Images ◽  
X Ray ◽  
Scanning Electron

Layer-structured polypyrrole/montmorillonite (PPy/MMT) naoncomposite films were synthesized by the electrodeposition method. The fabricated free-standing films consist of about 0∼2 wt% Na+-montmorillonite (NMMT). The thickness of films could be controlled by deposition time. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to observe the microstructure of the films. After MMT was introduced into the PPy matrix, the interspace between PPy chains decreased, according to the XRD results. The layered structure of the films was observed from the SEM images. Tensile and nanoindentation test results showed that the mechanical properties of the composite films were improved at low clay loading. The electrical conductivity of the films with 1.2 wt% MMT loading was increased from 3.6 to 51 S/cm, probably because of the restricted growth of PPy chains in the interspace of MMT layers.

scholarly journals Effects of annealing parameters on phase, structure and thermochromic properties of VO2 (M) derived from nanostructured VO2(B)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamdi Muhyuddin Barra ◽  
Soo Kien Chen ◽  
Nizam Tamchek ◽  
Zainal Abidin Talib ◽  
Oon Jew Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Different Temperatures ◽  
Thermochromic Properties ◽  
Scanning Electron

Abstract Synthesis of thermochromic VO2 (M) was successfully done by annealing hydrothermally-prepared VO2 (B) at different temperatures and times. Conversion of the metastable VO2 (B) to the thermochromic VO2 polymorph was studied using thermogravimetric analyzer (TGA) under N2 atmosphere. Moreover, the phase and morphology of the synthesized samples were studied using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. Accordingly, the XRD scans of all the annealed samples exhibited the presence of monoclinic VO2 (M), while the FE-SEM images of the samples showed the formation of nanorods and nanospheres, particularly those heated at high temperatures (650 °C and 700 °C). Meanwhile, differential scanning calorimetry (DSC) was used to measure the phase transition temperature (τc), hysteresis, and enthalpy of the prepared VO2. Based on these results, all samples displayed a τc of about 66 °C. However, the hysteresis was high for the samples annealed at lower temperatures (550 °C and 600 °C), while the enthalpy was very low for samples heated at lower annealing time (1.5 h and 1 h). These findings showed that crystallinity and nanostructure formation affected the thermochromic properties of the samples. In particular, the sample annealed at 650 °C showed better crystallinity and improved thermochromic behavior.

Characterizing the Image Forming Particles of Modern Ungilded Daguerreotypes Using XRD and SEM

2019 ◽  
Vol 25 (4) ◽  
pp. 1037-1051
Author(s):  
Patrick Ravines ◽  
Alexander Y. Nazarenko
Keyword(s):  
High Resolution ◽  
Diffraction Data ◽  
Regions Of Interest ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Cubic Crystals ◽  
X Ray ◽  
Silver Amalgam ◽  
Crystalline Nature ◽  
Scanning Electron

AbstractX-ray diffraction (XRD) and high-resolution scanning electron microscopy (SEM) have been used to characterize the silver mercury amalgam particles resting on the surface that comprise the image of five daguerreotype plates that were not gilded and that were prepared by three different contemporary daguerreotype makers. The regions of interest of the surface that were examined were overexposed, solarized, and highlight (white) areas. The XRD portion of the study shows that the two main silver mercury amalgam particles identified using the International Center for Diffraction Data PF4 + database were the Schachnerite/ζ (zeta) phase amalgam, Ag1.1Hg0.9, and the mercury silver amalgam, Ag0.65Hg0.35. On one of the daguerreotypes a third silver mercury amalgam, Moschellandsbergite, Ag2Hg3, was also identified in small concentrations. High-resolution SEM images corroborate the diffraction data and show that the crystalline nature of the silver mercury amalgam particles on all five plates to be mostly hexagonal, which would correspond to the Schachnerite/ζ (zeta) phase amalgam, and fewer rectangular solid and cubic crystals corresponding to the mercury silver amalgam.

Electrodeposited Ni-Co Films from Electrolytes with Different Co Contents

2021 ◽  
Vol 406 ◽  
pp. 219-228
Author(s):  
Ouahiba Herzallah ◽  
Hachemi Ben Temam ◽  
Asma Ababsa ◽  
Abderrahmane Gana
Keyword(s):  
Content Increase ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Hcp Structure ◽  
Xrd Patterns ◽  
Steel Substrates ◽  
Co Alloys ◽  
Scanning Electron

Ni–Co alloy coatings were electrodeposited at various cobalt amounts on pretreated steel substrates. The co-deposition phenomenon of Ni-Co alloys was described as anomalous behaviour. Different techniques including scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), X-ray diffraction (XRD) and potentiodynamic polarization were used to characterize the alloy coatings. EDX results showed that the Co content increase with the enhancing of Co amount. SEM images have shown that the increase of Co amount leads grain developing from large grain to branched grain form and that goes through spherical and pyramidal, this implies that the grain size of these alloy coatings is greatly affected by Co amount in the electrolyte baths. XRD patterns revealed that the phase structure of Ni–Co coatings is dramatically changed from fcc into hcp structure with the increase of Co amount. The electrochemical properties of Ni-Co alloy coatings evaluated in 3.5% NaCl solution reveal that Ni–34.32 wt.% Co alloy exhibits better corrosion resistance compared to pure Ni and other Ni–Co alloy coatings.

Study of the structure and lattice distortion on the sensing properties of hierarchical rutile TiO2 nanoarchitectures

2018 ◽  
Vol 11 (04) ◽  
pp. 1850073
Author(s):  
Carolina Silva-Carrillo ◽  
Balter Trujillo-Navarrete ◽  
Rosa María Felix-Navarro ◽  
Edgar Reynoso-Soto ◽  
Mirza Ruiz-Ramirez
Keyword(s):  
Aqueous Solution ◽  
Electrochemical Sensor ◽  
Lattice Distortion ◽  
X Ray Diffraction ◽  
Octahedral Structure ◽  
Future Studies ◽  
X Ray ◽  
Volatile Organic ◽  
Controlled Morphology ◽  
Scanning Electron

In this paper, we report the hydrothermal synthesis of 3D hierarchical rutile TiO2 nanorod microspheres in an acid medium with controlled morphology. Four different controlled hierarchical rutile TiO2 architectures (HRTA) characterized by X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM) were tested as an electrochemical sensor to quantify nitrobenzene (NB) in aqueous solution. Based on the characterization results, we found the open hierarchical nanorod microspheres with flower-like appearance showing a higher distortion of the octahedral structure and higher performance as an electrochemical sensor reaching NB concentrations below the parts per billion. The findings of this study have several valuable implications for future studies of volatile organic compound (COV) monitoring in aqueous solution using flower-like hierarchical rutile TiO2 nanorod microspheres clusters.

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