scholarly journals Structural and Optical Properties of Bi12NiO19 Sillenite Crystals: Application for the Removal of Basic Blue 41 from Wastewater

Photochem ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 319-329
Author(s):  
Billal Brahimi ◽  
Hamza Kenfoud ◽  
Yasmine Benrighi ◽  
Oussama Baaloudj
Keyword(s):  
Optical Properties ◽  
Rietveld Method ◽  
Combustion Method ◽  
Lattice Parameter ◽  
Environmental Applications ◽  
X Ray Diffraction ◽  
Narrow Bandgap ◽  
Bet Method ◽  
Visible Irradiation ◽  
First Time

This article covers the structural and optical property analysis of the sillenite Bi12NiO19 (BNO) in order to characterize a new catalyst that could be used for environmental applications. BNO crystals were produced by the combustion method using Polyvinylpyrrolidone as a combustion reagent. Different approaches were used to characterize the resulting catalyst. Starting with X-ray diffraction (XRD), the structure was refined from XRD data using the Rietveld method and then the structural form of this sillenite was illustrated for the first time. This catalyst has a space group of I23 with a lattice parameter of a = 10.24 Å. In addition, the special surface area (SSA) of BNO was determined by the Brunauer-Emmett-Teller (BET) method. It was found in the range between 14.56 and 20.56 cm2·g−1. Then, the morphology of the nanoparticles was visualized by Scanning Electron Microscope (SEM). For the optical properties of BNO, UV-VIS diffusion reflectance spectroscopy (DRS) was used, and a 2.1 eV optical bandgap was discovered. This sillenite′s narrow bandgap makes it an effective catalyst for environmental applications. The photocatalytic performance of the synthesized Bi12NiO19 was examined for the degradation of Basic blue 41. The degradation efficiency of BB41 achieved 98% within just 180 min at pH ~9 and with a catalyst dose of 1 g/L under visible irradiation. The relevant reaction mechanism and pathways were also proposed in this work.

scholarly journals Structural and Magnetic Property of Cr3+ Substituted Cobalt Ferrite Nanomaterials Prepared by the Sol-Gel Method

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2095 ◽  
Author(s):  
Jinpei Lin ◽  
Jiaqi Zhang ◽  
Hao Sun ◽  
Qing Lin ◽  
Zeping Guo ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Sol Gel ◽  
Combustion Method ◽  
Lattice Parameter ◽  
Cubic Phase ◽  
Cobalt Chromium ◽  
X Ray Diffraction ◽  
Chromium Doping ◽  
Auto Combustion ◽  
Cr Concentration

Cobalt-chromium ferrite, CoCrxFe2−xO4 (x = 0–1.2), has been synthesized by the sol-gel auto-combustion method. X-ray diffraction (XRD) indicates that samples calcined at 800 °C for 3 h were a single-cubic phase. The lattice parameter decreased with increasing Cr concentration. Scanning electron microscopy (SEM) confirmed that the sample powders were nanoparticles. It was confirmed from the room temperature Mössbauer spectra that transition from the ferrimagnetic state to the superparamagnetic state occurred with the doping of chromium. Both the saturation magnetization and the coercivity decreased with the chromium doping. With a higher annealing temperature, the saturation magnetization increased and the coercivity increased initially and then decreased for CoCr0.2Fe1.8O4.

scholarly journals The Role of Sintering Additives on Synthesis of High Performance Ceramic- Matrix Composites (Cmcs) by Volume Combustion in The Tio2–Al–C System: Structural and Mechanical Properties

2019 ◽  
Vol 3 (2) ◽  
Keyword(s):  
High Performance ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Combustion Method ◽  
Lattice Parameter ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Sintering Additives ◽  
Structural Applications ◽  
Tic Particle

The purpose of this work is to decrease or eliminate porosities in ETE-VC products with sintering additives. The Ti–C system has been synthesized for its advantages for refractory, abrasive and structural applications. We attempted to density TiC by using iron addition; this metal is introduced through a secondary reaction 3TiO3 +Al. This mixture reacts exothermically ϪH298= -1072.7 kJ and the heat is released according to by Fe addition 3TiO3 +4Al+3C+xFe→3TiC+2Al2 O3 +xFe. X-ray diffraction analysis indicated that intermetallic Fe3 Al, TiC and Al2 O3 are the main phases formed in the reinforced high performance ceramic-matrix composites and the additions of Fe decreased the lattice parameter of TiC. Field emission scanning electron microscopy examinations showed that the addition of Fe decreased TiC particle size and changed their growth controlling mechanism. Also, Raman spectroscopy analysis showed that at higher Fe contents, oxygen dissolved in the TiC crystal structure leading to the formation of titanium oxy-carbide with lower lattice parameter and residual un-reacted carbon in the products. The adiabatic temperatures for the reactions containing % Fe estimated using the thermodynamic data. Thus, doping method is finally used to fabricate materials by ETE-VC method (volume combustion method) for industriel applications.

The Role of Au Doping on the Structural and Optical Properties of Cu2O Films

2019 ◽  
Vol 58 ◽  
pp. 49-67 ◽  
Author(s):  
Emine Güneri
Keyword(s):  
Optical Properties ◽  
Crystal Size ◽  
Structural Parameters ◽  
Lattice Parameter ◽  
Skin Depth ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Polycrystalline Form ◽  
Doping Ratio

The changes in structural and optical properties of the Cu2O films obtained on the glass with different concentrations of Au by the chemical bath method were studied in this work. Lattice parameter, crystal size, preferential orientation and surface tension of the films were calculated using X-ray diffraction data which showed that all of the films were in polycrystalline form. It was determined that the structural parameters of all films were changed with the doping ratio. The surface morphology of the films was imaged using a field emission scanning electron microscope. The optical properties of the films were discovered using the optic spectrometer. Changes in the optical properties were discovered as a function of Au ratio. It was determined that the energy band gap value (2.12 eV-2.02 eV), the refractive index, the extinction coefficient, the real and dielectric coefficients, the optical conductivity, and the skin depth of films varied with Au doping ratio.

Influence of Li2+ Doping on the Structural and Optical Properties of CaO Synthesized by Sol–Gel Process

2019 ◽  
Vol 07 (01n02) ◽  
pp. 1950002
Author(s):  
Nadir Lalou ◽  
Ahmed Kadari
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Lithium Nitrate ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Sol Gel Process ◽  
Ft Ir ◽  
First Time

This work proposes the synthesis of nanocrystalline calcium oxide (CaO) pure and doped with different concentrations of lithium (Li[Formula: see text]) ions by sol–gel process. Calcium nitrate (Ca(NO[Formula: see text]4H2O; 99.99%) and lithium nitrate (LiNO3; 99.99%) were used as precursors. The synthesized powders were characterized by several techniques such as: UV-Vis transmission spectroscopy, Fourier Transform Infra-red spectroscopy (FT-IR) and X-ray diffraction (XRD). The main objective of this paper is to study the influence of lithium (Li[Formula: see text] ratio) on the structural and optical properties of synthesized powders. The band gap values decreased with the increasing of Li[Formula: see text] ions in CaO lattice; the slight change in the band gap was directly related to the energy transfer between the CaO excited states and the 2s levels of Li[Formula: see text] ions. The influence of Li[Formula: see text] doping on the physical properties of CaO nanocrystalline will be studied for the first time in this work; no literature has previously published this kind of impurities.

Study of Crystallite Size of Yttria-Stabilized Zirconia Powders by Rietveld Method

2010 ◽  
Vol 660-661 ◽  
pp. 965-970 ◽  
Author(s):  
Wellington Claiton Leite ◽  
Adriana Scoton Antonio Chinelatto ◽  
André Maurício Brinatti ◽  
Mauricio Aparecido Ribeiro ◽  
André Vitor Chaves de Andrade ◽  
...  
Keyword(s):  
Rietveld Method ◽  
Pechini Method ◽  
Lattice Parameter ◽  
Yttria Stabilized Zirconia ◽  
Crystalline Size ◽  
Cubic Phase ◽  
Average Crystalline Size ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Atomic Scattering

The yttria-stabilized zirconia (YSZ) is used in a great variety of applications, for example, electrolytes of solid oxide fuel cells and oxygen sensors. In the study of YSZ, the particle size powders and sintering processes are important to define the final properties of the zirconia products. The objectives of this work were to determine the phases and the crystalline size using X-Ray Diffraction (XRD) data and the Rietveld Method (RM) of the YSZ powders obtained by chemical synthesis based on the Pechini method. It was used ZrOCl2.8H2O and Y(NO3)3.5H2O as precursors reagents. After calcination at 550oC during 24 hours, the powder was analyzed by XRD and scanning electronic microscopy (SEM). From XRD and using Rietveld method were verified that there is only cubic phase with lattice parameter a = 5.1307(1) Å and the space group Fm3m. Due to substitution of the Zr atoms in the Y atoms sites, there were vacancies in 17.72 % of O atoms sites. However, the percentage of substitution of Zr atoms in Y atoms sites in the structure not was determinate because the curves of atomic scattering of them are very similar. Using Scherrer equation and considering anisotropy effect, the average crystalline size was determinate: 10,43 nm (c axis) and 10,39 (b axis). This spherical symmetry also observed for SEM.

Frequency dependence and fuel effect on optical properties of nano TiO2-based structures

2016 ◽  
Vol 30 (18) ◽  
pp. 1650247 ◽  
Author(s):  
Mahdi Ghasemifard ◽  
Misagh Ghamari ◽  
Meysam Iziy
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Average Particle Size ◽  
Combustion Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
Transmission Electron ◽  
Auto Combustion ◽  
Xrd Patterns

TiO2-(Ti[Formula: see text]Si[Formula: see text]O2 nanopowders (TS-NPs) with average particle size around 90 nm were successfully synthesized by controlled auto-combustion method by using citric acid/nitric acid (AC:NA) and urea/metal cation (U:MC). The structure of powders was studied based on their X-ray diffraction (XRD) patterns. The XRD of TS-NPs shows that rutile and anatase are the main phases of TS-NPs for AC:NA and U:MC, respectively. Particle size and histogram of nanopowders were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Optical properties of TS-NPs were calculated by Fourier transform infrared spectroscopy (FTIR) and Kramers–Kroning (KK) relation. Plasma frequencies of TS-NPs obtained from energy loss functions depend on fuels as a result of changes in crystal structure, particle size distribution, and morphology.

Oxygen-Induced Reversible Structural Change of Supported fine Silver Particles Observed by In Situ Optical Absorption and X-ray Diffraction

1990 ◽  
Vol 195 ◽  
Author(s):  
Akihisa Yanase ◽  
Hiroshi Komiyama ◽  
Kazunobu Tanaka
Keyword(s):  
Optical Absorption ◽  
Surface Stress ◽  
Lattice Parameter ◽  
Silver Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ambient Gases ◽  
First Time ◽  
Shape Of Particles

ABSTRACTIn situ measurements of optical absorption and x-ray diffraction for small supported silver particles were performed under defined atmospheres at temperatures below 723 K. We found, for the first time, reversible changes both in optical absorption spectrum and lattice parameter of silver particles against the cyclic exchange of ambient gases between 5% H2/He and 1% 02/He. The present data indicate that the adsorption of oxygen results in a reduction in surface stress of silver particles, leading to a change in the shape of particles.

scholarly journals Influence of Ni substitution on structural, morphological, dielectric, magnetic and optical properties of Cu–Zn ferrite by double sintering sol–gel technique

2019 ◽  
Vol 09 (02) ◽  
pp. 1950020 ◽  
Author(s):  
Mohammad Sajjad Hossain ◽  
Yeasmin Akter ◽  
Mohammad Shahjahan ◽  
Muhammad Shahriar Bashar ◽  
Most. Hosney Ara Begum ◽  
...  
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Combustion Method ◽  
Lattice Parameter ◽  
Munk Function ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Elemental Analyses ◽  
Gel Technique

Polycrystalline NiCuZn ferrite (NixCu[Formula: see text]Zn[Formula: see text]Fe2O4; [Formula: see text], 0.3, 0.4 and 0.5) were prepared through sol–gel auto combustion method applying double sintering technique. Structural, morphological, elemental analyses (EDS), Fourier-transform infrared spectroscopy (FTIR), Direct Current (DC) electrical resistivity, dielectric, magnetic and optical properties of prepared samples were analyzed. XRD profiles reveal the formation of simple cubic spinel structure without any traceable impurity. The average crystallite size lies within the range of 22–29[Formula: see text]nm. Lattice parameter decreases with increasing Ni concentration. Room temperature DC resistivity was recorded from [Formula: see text] to [Formula: see text][Formula: see text][Formula: see text][Formula: see text]cm. Both dielectric constant ([Formula: see text]) and loss factor (tan[Formula: see text]) were decreased with increase of frequency while AC conductivity increases. FTIR absorption peak occurred at three different frequency ranges at 570–577[Formula: see text]cm[Formula: see text], 1635–1662[Formula: see text]cm[Formula: see text] and 3439–3448[Formula: see text]cm[Formula: see text]. Magnetic properties were investigated by using vibrating sample magnetometer (VSM). Decreasing trends were observed for saturation magnetization ([Formula: see text]), magnetic coercivity ([Formula: see text]) and remanant magnetization ([Formula: see text]) with the increase of Ni content. Optical band gap ([Formula: see text]2.70–2.79[Formula: see text]eV) were calculated from diffuse reflectance data by using Kubelka–Munk function.

X-ray structure determination of the rare earth oxides (Er1−uGdu)2O3applying the Rietveld method

2002 ◽  
Vol 35 (5) ◽  
pp. 577-580 ◽  
Author(s):  
Zein Heiba ◽  
Hasan Okuyucu ◽  
Y. S. Hascicek
Keyword(s):  
Rare Earth ◽  
Rietveld Method ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Average Size

Nanosized polycrystalline samples of (Er1−uGdu)2O3(0 ≤u≤ 1.0) were synthesized by a sol–gel technique. X-ray diffraction data were collected and the crystal structures were refined by the Rietveld method. All samples are found to have the same crystal system and formed solid solutions over the whole range ofu. The Er3+and Gd3+ions were randomly distributed over two cationic sites, 8band 24d, in the space groupIa\bar{3} (206) in all refined structures. The lattice parameter was found to vary non-linearly with the composition (u). The average microstrain and average crystallite size have been calculated from the Williamson–Hall plots for each sample. The average size ranges from 50 to 70 nm, and the microstrain from 0.4 to 1.7%.

SYNTHESIS AND PHOTOLUMINESCENCE PROPERTIES OF Er3+, Eu3+ IONS ACTIVATED SrAl12O19

2006 ◽  
Vol 20 (29) ◽  
pp. 4891-4898 ◽  
Author(s):  
VIJAY SINGH ◽  
JUN-JIE ZHU
Keyword(s):  
Optical Properties ◽  
Combustion Method ◽  
Photoluminescence Spectra ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminate Phosphor

Synthesis of Er 3+, Eu 3+ ions activated strontium hexa-aluminate phosphor using the combustion method is described. An efficient phosphor can be prepared by this method at reaction temperatures as low as 500°C in a few minutes. Powder X-ray diffraction and the optical properties were studied by photoluminescence spectra.

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