scholarly journals Carbothermal Reduction Nitridation of Fly Ash, Diatomite and Raw Illite: Formation of Nitride Powders with Different Morphology and Photoluminescence Properties

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 409
Author(s):  
Kuizhou Dou ◽  
Yinshan Jiang ◽  
Bing Xue ◽  
Cundi Wei ◽  
Fangfei Li
Keyword(s):  
Fly Ash ◽  
Alkali Metals ◽  
Blue Shift ◽  
Pulverized Coal ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Nitridation Process ◽  
Ft Ir ◽  
Lower Temperature ◽  
Rare Earth Doped

Rare-earth-doped SiAlON and Si3N4 materials from aluminosilicate starting materials have been reported to show superior photoluminescence (PL) properties. Three different starting materials, including pulverized coal furnace fly ash, diatomite and raw illite, were used for synthesis of nitride materials. The phase and morphology evolution of these products were carefully monitored at the low temperature range of 1350 °C to 1450 °C by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR). The PL properties of Eu-doped nitride products were also comparatively characterized. The results show that the type of starting material affects the phase composition and the photoluminescence properties of products. The existence of aluminum and alkali metals could effectively promote nitridation reactions. Aluminum in the starting materials led to the formation of different aluminum-rich nitride phases. Thus, β-SiAlON could be achieved at a much lower temperature (1350 °C) using raw illite or fly ash containing the proper amount of aluminum. Additionally, excess aluminum led to the formation of corundum and 15R-SiAlON. The products from pulverized coal furnace fly ash had more prismatic particles, and the products from diatomite had more fibrous particles. With the progress of the nitridation process, the fibers were increased, becoming longer and straighter, and the prismatic particles were more obvious. The presence of aluminum in the starting materials led to a blue shift in the photoluminescence spectrum.

scholarly journals An accelerated and effective synthesis of zinc borate from zinc sulfate using sonochemistry

2020 ◽  
Vol 43 (1) ◽  
pp. 7-14
Author(s):  
Ali Can Ersan ◽  
Azmi Seyhun Kipcak ◽  
Meral Yildirim Ozen ◽  
Nurcan Tugrul
Keyword(s):  
Inorganic Compounds ◽  
Zinc Borate ◽  
High Yield ◽  
X Ray Diffraction ◽  
Ultrasonic Probe ◽  
Minimum Particle Size ◽  
Effective Synthesis ◽  
Ft Ir ◽  
Lower Temperature ◽  
Borate Compound

AbstractRecently, sonochemistry has been used for the synthesis of inorganic compounds, such as zinc borates. In this study using zinc sulphate heptahydrate (ZnSO4·7H2O) and boric acid (H3BO3) as starting materials, a zinc borate compound in the form of Zn3B6O12·3.5H2O was synthesized using an ultrasonic probe. Product’s characterization was carried out with using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy. Zinc borate compound’s chemical bond structure was observed with Raman and FTIR. From the XRD results it was seen that Zn3B6O12·3.5H2O can be quickly synthesized upon heating at 80°C and 85°C (55 min) or 90°C (45 min) in very high yield (>90%). The minimum particle size obtained was ~143 μm from the SEM results. Zinc borate compound was synthesized at a lower temperature in less time than other synthesized zinc metal compound in literature.

Hydrothermal Synthesis and Photoluminescence Properties of Ca(MoO4)x(WO4)(1-X) Microcrystallines

2013 ◽  
Vol 652-654 ◽  
pp. 599-606
Author(s):  
Yan Zhao ◽  
Yan Yan Wei ◽  
Dan Qin ◽  
Xin Lai ◽  
Yun Wu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Uv Light ◽  
Emission Spectra ◽  
Fluorescence Analysis ◽  
Tetragonal Symmetry ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Structure Surface ◽  
Ft Ir

Ca(MoO4)x(WO4)(1-x)solid solution microcrystallines were synthesized by hydrothermal method at 120 °C; the crystal structure, surface morphology and room temperature photoluminescence properties of the as-synthesized microcrystallines were investigated by through X-ray diffraction (XRD), scanning electron micrograph (SEM), Fourier transform infrared spectroscopy (FT-IR) and fluorescence analysis (FA), respectively. Our results show that the obtained Ca(MoO4)x(WO4)(1-x)microcrystallines are single-phase scheelite structure with tetragonal symmetry. The grain size of the Ca(MoO4)x(WO4)(1-x) microcrystallines gradually increases with the increasing x (except x=0) and their agglomeration also becomes serious with x increasing. Under excited by 245 nm or 280 nm ultraviolet light (UV-light) at room temperature, the emission spectra of the Ca(MoO4)x(WO4)(1-x) microcrystallines vary slightly from 410nm to 490nm with increasing x. Whereas the emission intensity of Ca(MoO4)x(WO4)(1-x) microcrystallines changed markedly, and it increases with the increasing x (x＞0).

Green Synthesis of Silver Nanoparticles Using a Terrestrial Weed Mucuna bracteata DC and Their Adsorption Study on Reactive Red 120

2020 ◽  
Vol 12 (2) ◽  
pp. 207-214
Author(s):  
N. Mahalaxmi ◽  
E. V. Ramasamy
Keyword(s):  
Dye Removal ◽  
Adsorption Process ◽  
Silver Ions ◽  
Blue Shift ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Reactive Red 120 ◽  
Pseudo Second Order ◽  
Ft Ir

An eco-friendly method of silver nanoparticle (SNPs) synthesis is presented by utilizing a terrestrial weed, Mucuna bracteata DC. This plant based nanoparticles are effectively reducing anionic dye, Reactive Red 120 by adsorption—an effective method of dye removal from effluents. The method enables the rapid synthesis of SNPs at ambient conditions without any use of hazardous chemicals. The characterization of nanoparticles with UV-visible spectrophotometer indicated the absorption peak at 299 of blue shift; SEM and TEM analysis has revealed the presence of particles with spherical morphology of about 30–80 nm in size; The X-ray diffraction and EDAX studies confirmed the presence of silver atoms; The FT-IR spectra indicated the role of hydroxyl functional groups and amino group of the phyto extract, are responsible for the reduction and stabilizing silver ions in to SNPs. The dye removal results showed that the adsorption process increases when the concentration of nanoparticles increases. The adsorption process obeys Langmuir isotherm (R2 value were 0.994 and RL value lies between 0 and 1) and pseudo second order kinetics (R2 value were 0.998) more effectively. The isotherm and kinetic model confirmed that Mucuna bracteata based SNPs can be used as a suitable adsorbent for the removal of dyes from effluents.

scholarly journals Fabrication and characterization of Zn doped CuO nanofiber using newly designed nanofiber generator for the photodegradation of methylene blue from textile effluent

2018 ◽  
Vol 36 (3) ◽  
pp. 520-529 ◽  
Author(s):  
Ramasamy Gopalsamy Sethuraman ◽  
Thangamuthu Venkatachalam ◽  
Selvaraj Dinesh Kirupha
Keyword(s):  
Methylene Blue ◽  
Copper Oxide ◽  
Copper Acetate ◽  
Average Crystallite Size ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Ft Ir ◽  
The Stability

AbstractHigh aspect ratio, Zn doped copper oxide (Zn-CuO) nanofibers have been fabricated employing a newly designed electrospun coating unit using copper acetate, sodium hydroxide and polyethylene glycol in aqueous state. The prepared Zn doped copper oxide (Zn-CuO) nanofibers were sintered at 400 °C, 500 °C and 600 °C separately and characterized using X-ray diffraction XRD, Fourier transformation infrared spectroscopy FT-IR, scanning electron microscopy SEM, energy dispersive spectroscopy EDS. The average crystallite size was in the range of 28 nm to 30 nm. Optical properties of Zn-CuO nanofibers were analyzed using UV-DRS studies which showed a blue shift in the absorption band. An increase in band gap with the increase in postannealing temperature was observed due to the blue shift in absorption edge of CuO causing enhanced photodegradation. The catalytic properties of the CuO nanofibers were tested using methylene blue in aqueous medium. The influences of parameters responsible for high photodegradation were optimized and the rate of the photodegradation process was calculated using photodegradation kinetics. The reusability test was conducted to find the stability of the fabricated Zn-CuO nanofibers.

scholarly journals A novel three-dimensional copper aspartate coordination compound with efficient photoluminescence

2020 ◽  
Vol 75 (3) ◽  
pp. 281-286
Author(s):  
Si Shu ◽  
Yun-Fei Jian ◽  
Tong Zhang ◽  
Wen-Long Guo ◽  
Xi Liu
Keyword(s):  
Three Dimensional ◽  
Solvothermal Reaction ◽  
Water Molecules ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Nanoporous Copper ◽  
Rectangular Channels ◽  
Ft Ir ◽  
Copper Cations ◽  
Ft Ir Spectroscopy

AbstractSolvothermal reaction of a copper salt, racemic aspartic acid (AspH3), and 1,2,4-triazole (TaH) leads to a nanoporous copper aspartate, Cu4(Asp)2(Ta)2(H2O)2 · 2H2O (1). The compound was characterized by FT-IR spectroscopy and elemental analysis, and the structure was determined by single-crystal X-ray diffraction. Pairs of l-Asp3− and d-Asp3− ligands in unprecedented μ4-1,2κO:3,4κOκN coordination modes chelate pairs of adjacent copper cations to form a centrosymmetric 8n-membered rectangular pipe, and these pipes are further bridged by copper cations in four directions of the bc plane to form a 3D porous structure with approximately rectangular channels of  ~ 5 × 10 Å2 along the crystallographic a-axis. Along the corners of the rectangular channels, each Ta− ligand connects three adjacent copper cations in a μ3 coordination mode to form the final 3D porous framework with relatively large rectangular channels of  ~ 2 × 8 Å2 along the a-axis. Water molecules reside in these large channels. The thermal stability and solid-state photoluminescence properties of the title compound are also investigated.

scholarly journals A comparative study of the utilization of synthetic foaming agent and aluminum powder as pore-forming agents in lightweight geopolymer synthesis

2019 ◽  
Vol 17 (1) ◽  
pp. 629-638 ◽  
Author(s):  
Ufafa Anggarini ◽  
Suminar Pratapa ◽  
Victor Purnomo ◽  
Ndaru Candra Sukmana
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Aluminum Powder ◽  
X Ray Diffraction ◽  
Foaming Agent ◽  
Weight Percentage ◽  
Ash Weight ◽  
Ft Ir ◽  
Powder Addition ◽  
Geopolymer Paste

AbstractLightweight geopolymer concrete was synthesized using fly ash as an aluminosilicate source with the addition of a pore-forming agent. The synthesis of a geopolymer was conducted by employing various volume ratios of geopolymer paste to the foaming agent: 1:0.50, 1:0.67, 1:0.75, 1:1.00, 1:1.33, 1:1.50, and 1:2.00, while the ratios of aluminum powder weight percentage to the fly ash weight varied between 0.01 - 0.15 %wt. The results showed that the higher foaming agent content, the lower the compressive strength and density of the geopolymer. The ratio of the geopolymer paste to the foaming agent, 1:1.33 was found to produce the strongest light weight geopolymer whose compressive strength and density were 33 MPa and 1760 kg/m3, respectively. With the addition of 0.01%wt aluminum powder, the geopolymer specimen showed the highest compressive strength of 42 MPa and density of 1830 kg/m3, respectively. X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and FT-IR were utilized to study the effects of foaming agent and aluminum powder addition onto the microstructure, surface morphology, and functional groups of the geopolymer. Both types of synthesized geopolymers have the potential to be developed in terms of compressive strength and density in the future.

A new stepped tetranuclear copper(II) complex: synthesis, crystal structure and photoluminescence properties

2017 ◽  
Vol 73 (5) ◽  
pp. 393-398 ◽  
Author(s):  
Elif Gungor
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Uv Light ◽  
Visible Region ◽  
Blue Emission ◽  
Green Emission ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Vis Spectroscopy ◽  
Ft Ir

Binuclear and tetranuclear copper(II) complexes are of interest because of their structural, magnetic and photoluminescence properties. Of the several important configurations of tetranuclear copper(II) complexes, there are limited reports on the crystal structures and solid-state photoluminescence properties of `stepped' tetranuclear copper(II) complexes. A new CuII complex, namely bis{μ3-3-[(4-methoxy-2-oxidobenzylidene)amino]propanolato}bis{μ2-3-[(4-methoxy-2-oxidobenzylidene)amino]propanolato}tetracopper(II), [Cu4(C11H13NO3)4], has been synthesized and characterized using elemental analysis, FT–IR, solid-state UV–Vis spectroscopy and single-crystal X-ray diffraction. The crystal structure determination shows that the complex is a stepped tetranuclear structure consisting of two dinuclear [Cu2(L)2] units {L is 3-[(4-methoxy-2-oxidobenzylidene)amino]propanolate}. The two terminal CuII atoms are four-coordinated in square-planar environments, while the two central CuII atoms are five-coordinated in square-pyramidal environments. The solid-state photoluminescence properties of both the complex and 3-[(2-hydroxy-4-methoxybenzylidene)amino]propanol (H2 L) have been investigated at room temperature in the visible region. When the complex and H2 L are excited under UV light at 349 nm, the complex displays a strong blue emission at 469 nm and H2 L displays a green emission at 515 nm.

The Effect of Fly Ash on TSA of Cementitous Material: Based on Three Years Results

2013 ◽  
Vol 539 ◽  
pp. 139-144
Author(s):  
Ben Wan Liu ◽  
Chang Hui Yang ◽  
Xiao Bin Xiang ◽  
Lin Wen Yu ◽  
Jing Zhang
Keyword(s):  
Fly Ash ◽  
Sulfate Solution ◽  
Sulfate Attack ◽  
Hardened Cement ◽  
Hydration Reaction ◽  
X Ray Diffraction ◽  
Hardened Cement Paste ◽  
X Ray ◽  
Ft Ir ◽  
Secondary Hydration

The thaumasite form of sulfate attack of cementitous material (TSA) is a new kind of sulfate attack and it is more harmful than traditional sulfate attack. By means of Fourier transform infrared (FT-IR) and X-ray diffraction (XRD), the effect of dosage and fineness of fly ash on TSA of cementitous material were investigated in this paper. The specimens had been immersed in magnesium sulfate solution of 5% mass concentration at 5±2° C for three years. The results showed that fly ash could not restrain the formation of thaumasite but it delayed the occurrence of TSA in cementitous material when 30% fly ash takes place of cement. Fly ash could enhance the resistance of cementitous material to TSA through secondary hydration reaction to optimizing the pore structure of hardened cement paste and lowering the C/S of C-S-H gel.

scholarly journals Effect of Alkali Activator on the Standard Consistency and Setting Times of Fly Ash and GGBS-Based Sustainable Geopolymer Pastes

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
M. Dineshkumar ◽  
C. Umarani
Keyword(s):  
Fly Ash ◽  
Setting Time ◽  
Fluorescence Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alkali Activator ◽  
Setting Times ◽  
Granulated Blast Furnace Slag ◽  
Ft Ir ◽  
Alkaline Activator

In this study, an attempt has been made to study the effect of alkali activator on the standard consistency and setting times of low calcium fly ash (FA) and ground granulated blast furnace slag (GGBS)- based sustainable geopolymer pastes. Different proportions of FA and GGBS were blended into mixes of geopolymer paste using sodium hydroxide (SH) and sodium silicate (SS) as alkaline activator solution (AAS). Tests on geopolymer pastes for consistency and initial and final setting times were carried out for three different SH : SS ratios of 1 : 1, 1 : 2, and 1 : 3 for both 2.5 M (molarity) and 5.0 M of SH concentration. While increasing the molarity of SH, both consistency and setting time decreased. For all the blended binder mix, the setting time decreases with an increase in the quantity of SS in the alkali activator solution. An increase in the amount of GGBS content in the geopolymer blended binder mix increases the consistency and decreases the setting time. For both 2.5 M and 5 M blended geopolymer mixes, a decrease in the percentage of GGBS and an increase in the percentage of FA increased the setting time. Microstructural studies such as X-ray fluorescence analysis (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR) analyses were carried out, and the results are presented. The FT-IR spectra for the blended binder mixes demonstrated the formation of geopolymerization and the presence of the functional groups.

scholarly journals Comparative Study of Complexes of Rare Earths and Actinides with 2,6-Bis(1,2,4-triazin-3-yl)pyridine

Inorganics ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 26 ◽  
Author(s):  
Attila Kovács ◽  
Christos Apostolidis ◽  
Olaf Walter
Keyword(s):  
Blue Shift ◽  
X Ray Diffraction ◽  
Covalent Character ◽  
Ionic Radii ◽  
X Ray ◽  
Group Iii ◽  
Exchange Correlation ◽  
Ligand Interactions ◽  
Ft Ir ◽  
Metal Ligand

Complexes of group III metals (rare earth and actinides) with 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (BTP) have been investigated by computational (DFT) and, in limited cases, by experimental (FT-IR, X-ray) techniques with the goal of determining the characteristics of metal–ligand interactions. The DFT calculations using the M062X exchange-correlation functional revealed that metal–ligand distances correlate with the ionic radii of the metals, in agreement with available X-ray diffraction results on the Sc, Y, La, U, and Pu complexes. A related blue-shift trend could be observed in seven characteristic bands in the IR spectra associated with metal–ligand vibrations. The computations uncovered considerable charge transfer interactions, particularly in the actinide complexes, as important covalent contributions to the metal–ligand bonding. The covalent character of the metal–ligand bonds decreases in the actinides, from U to Cm.

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