Ambient Condition Synthesis of Ag Submicron Crystallites from AgNO3, H2O2 and NH3•H2O

2011 ◽  
Vol 391-392 ◽  
pp. 1392-1395
Author(s):  
Jing Li ◽  
Yong Cai Zhang
Keyword(s):  
Aqueous Solutions ◽  
Atmospheric Pressure ◽  
Cost Effective ◽  
Cubic Phase ◽  
Present System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cost Effective Method ◽  
Diffraction Patterns ◽  
Microscopy Images

A simple and cost-effective method based on the reduction of AgNO3 by H2O2 (5 vol.%) in 2.5–5 vol.% NH3•H2O aqueous solutions at room temperature and under atmospheric pressure was developed for the synthesis of Ag submicron crystallites. X-ray diffraction patterns demonstrated that the resultant products were pure cubic phase Ag powders. Field emission scanning electronic microscopy images showed that the Ag powders synthesized in 2.5 and 5 vol.% NH3•H2O aqueous solutions comprised submicron crystallites with the sizes of about 355–580 and 200–650 nm, respectively. Besides, the possible formation mechanism of Ag powders in the present system was also proposed.

Facile Refluxing Synthesis of Hydroxyapatite Nanoparticles

2015 ◽  
Vol 68 (8) ◽  
pp. 1293 ◽  
Author(s):  
Pakvipar Chaopanich ◽  
Punnama Siriphannon
Keyword(s):  
Crystallite Size ◽  
Reaction Times ◽  
Single Step ◽  
Hydroxyapatite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Aqueous Mixture ◽  
Diffraction Patterns ◽  
Microscopy Images

Hydroxyapatite (HAp) nanoparticles were successfully synthesized from an aqueous mixture of Ca(NO3)2·4H2O and (NH4)2HPO4 by a facile single-step refluxing method using polystyrene sulfonate (PSS) as a template. The effects of reaction times, pH, and PSS concentration on the HAp formation were investigated. It was found that the crystalline HAp was obtained under all conditions after refluxing the precursors for 3 and 6 h. The longer refluxing time, the greater the crystallinity and the larger the crystallite size of the HAp nanoparticles. The HAp with poor crystallinity was obtained at pH 8.5; however, the well-crystallized HAp was obtained when reaction pH was increased to 9.5 and 10.5. In addition, the X-ray diffraction patterns revealed that the presence of PSS template caused the reduction of HAp crystallite size along the (002) plane from 52.6 nm of non-template HAp to 43.4 nm and 41.4 nm of HAp with 0.05 and 0.2 wt-% PSS template, respectively. Transmission electron microscopy images of the synthesized HAp revealed the rod-shaped crystals of all samples. The synthesized HAp nanoparticles were modified by l-aspartic acid (Asp) and l-arginine (Arg), having negative and positive charges, respectively. It was found that the zeta potential of HAp was significantly changed from +5.46 to –24.70 mV after modification with Asp, whereas it was +4.72 mV in the Arg-modified HAp. These results suggested that the negatively charged amino acid was preferentially adsorbed onto the synthesized HAp surface.

scholarly journals Enhanced fluorescence of selected cationic dyes adsorbed on reduced-charge montmorillonite

Clay Minerals ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 93-103 ◽  
Author(s):  
P. Pustková ◽  
Z. Klika ◽  
J. Preclíková ◽  
T. M. Grygar
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Nile Blue ◽  
Cationic Dyes ◽  
X Ray Diffraction ◽  
Enhanced Fluorescence ◽  
Visible Absorption ◽  
X Ray ◽  
Diffraction Patterns

AbstractThe aggregation of three cationic dyes (CD), crystal violet (CV), Nile blue (NB) and rhodamine B (RB) in aqueous solution was studied by visible absorption spectrophotometry and compared with methylene blue (MB). The distribution of the dye species (monomers, dimers, trimers, and tetramers) in aqueous solutions with different concentrations of dye was calculated using equilibrium stepwise aggregation constants Kn. These cationic dyes were intercalated into montmorillonite (SAz-1) and its reduced charge form (RC-SAz(210)) prepared by heating lithium montmorillonite (Li/SAz-1) at 210ºC. The fluorescence of fully saturated CD/SAz and low-CD loaded CD/RC-SAz(210) complexes was studied. Visible absorption spectra of CD aqueous solutions and visible absorption spectra and X-ray diffraction patterns (d001) of the CD/SAz and CD/RC-SAz( 210) solid complexes were obtained and evaluated. Large fluorescence intensities were found for CV/RC-SAz(210) and NB/RC-SAz(210) complexes in the same way as for the complex of methylene blue with reduced-charge montmorillonite MB/RCM(210) described previously.

scholarly journals Quantification of Kaolinite and Halloysite Using Machine Learning from FTIR, XRF, and Brightness Data

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1350
Author(s):  
Pieter I. Du Plessis ◽  
Michael F. Gazley ◽  
Stephanie L. Tay ◽  
Eliza F. Trunfull ◽  
Manuel Knorsch ◽  
...  
Keyword(s):  
Cost Effective ◽  
X Ray Diffraction ◽  
Yilgarn Craton ◽  
Weathering Profile ◽  
X Ray ◽  
Clay Deposits ◽  
Cost Effective Method ◽  
Cost Effective Alternative ◽  
Quantified Analysis

Quantification of halloysite and kaolinite in clay deposits from X-ray diffraction (XRD) commonly requires extensive sample preparation to differentiate the two phyllosilicates. When assessing hundreds of samples for mineral resource estimations, XRD analyses may become unfeasible due to time and expense. Fourier transform infrared (FTIR) analysis is a fast and cost-effective method to discriminate between kaolinite and halloysite; however, few efforts have been made to use this technique for quantified analysis of these minerals. In this study, we trained machine- and deep-learning models on XRD data to predict the abundance of kaolinite and halloysite from FTIR, chemical composition, and brightness data. The case study is from the Cloud Nine kaolinite–halloysite deposit, Noombenberry Project, Western Australia. The residual clay deposit is hosted in the saprolitic and transition zone of the weathering profile above the basement granite on the southwestern portion of the Archean Yilgarn Craton. Compared with XRD quantification, the predicted models have an R2 of 0.97 for kaolinite and 0.96 for halloysite, demonstrating an excellent fit. Based on these results, we demonstrate that our methodology provides a cost-effective alternative to XRD to quantify kaolinite and halloysite abundances.

scholarly journals Solvent-deficient synthesis of nanocrystalline Ba0.5Sr0.5Co0.8Fe0.2O3-δ powder

2018 ◽  
Vol 12 (4) ◽  
pp. 342-349 ◽  
Author(s):  
Sasa Zeljkovic ◽  
Jin Miyawaki ◽  
Dragoljub Vrankovic ◽  
Elena Tervoort ◽  
Roland Hauert ◽  
...  
Keyword(s):  
Thermal Analyses ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Ammonium Bicarbonate ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Rapid Synthesis ◽  
X Ray ◽  
Metal Nitrates

Nanocrystalline Ba0.5Sr0.5Co0.8Fe0.2O3-? powders were prepared by a cost-effective solvent-deficient method using metal nitrates and ammonium bicarbonate as precursors. X-ray diffraction (XRD), specific surface determination (BET), thermal analyses (TG-DTA-DSC), dynamic light scattering (DLS) and scanning electron microscopy (SEM) were used to examine the effects of the calcination temperature on the Ba0.5Sr0.5Co0.8Fe0.2O3-? (BSCF) formation. XRD analysis showed that a cubic Ba0.5Sr0.5Co0.8Fe0.2O3-? was obtained after heating for 1 h at 1000?C. BSCF nanocrystals with a diameter of about 25 nm were obtained. On the other hand, the sample mass was stabilized at 915?C as recorded by thermogravimetric analysis (TG), indicating a formation of the complex BSCF oxide already at this temperature. The phase transformations during the synthesis of BSCF oxide are defined and confirmed with the note on the instability of the cubic phase. Using the four-point DC measurements between ?73?C and 127?C, the band gap of 0.84 eV was determined. The solvent-deficient method used in this study to synthesize Ba0.5Sr0.5Co0.8Fe0.2O3-? showed distinct advantages in comparison with other synthesis techniques considering simplicity, rapid synthesis, and quality of the produced nanocrystals.

scholarly journals Photocatalytic Degradation of Methylene Blue and Metanil Yellow Dyes Using Green Synthesized Zinc Oxide (ZnO) Nanocrystals

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 22
Author(s):  
S. Shwetha Priyadharshini ◽  
Jayachamarajapura Pranesh Shubha ◽  
Jaydev Shivalingappa ◽  
Syed Farooq Adil ◽  
Mufsir Kuniyil ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Cost Effective ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zno Nanocrystals ◽  
Cost Effective Method ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Metanil Yellow

In this work, ZnO nanocrystals (NCs) have been effectively synthesized by a simple, efficient and cost-effective method using coconut husk extract as a novel fuel. The synthesized NCs are characterized by UV-Vis, XRD, FT-IR, SEM, EDX, Raman and PL studies. The obtained ZnO were found to be UV-active with a bandgap of 2.93 eV. The X-ray diffraction pattern confirms the crystallinity of the ZnO with hexagonally structured ZnO with a crystallite size of 48 nm, while the SEM analysis reveals the hexagonal bipyramid morphology. Photocatalytic activities of the synthesized ZnO NCs are used to degrade methylene blue and metanil yellow dyes.

Intergrowth of several solid phases from the Y–Ni–B–C system in a large YNi2B2C crystal

2008 ◽  
Vol 41 (4) ◽  
pp. 738-746 ◽  
Author(s):  
Torsten Weissbach ◽  
Tilmann Leisegang ◽  
Andreas Kreyssig ◽  
Matthias Frontzek ◽  
Jens-Uwe Hoffmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
Orientation Relation ◽  
X Ray ◽  
Polished Cross Section ◽  
Diffraction Patterns ◽  
The Individual ◽  
Microscopy Images ◽  
Scanning Electron

A YNi2B2C single crystal containing traces of foreign phases was inspected by means of neutron and X-ray diffraction as well as scanning electron microscopy and X-ray spectroscopy methods. The diffraction patterns obtained from the experiments look similar to those expected for a superstructure. Nevertheless, they can be interpreted as crystallographically oriented precipitations of YB2C2and Ni2B within the YNi2B2C crystal, formed during the cooling process. The orientation relation between the lattices was obtained from experimental neutron and X-ray data. Structure refinements of the collected X-ray data were performed by separation of the intensity data of the individual phases. Scanning electron microscopy images of the inclusions found on a polished cross section of the crystal are presented; their chemical composition was determined using wavelength-dispersive X-ray analysis.

Modification of Ge2Sb2Te5 by the Addition of SiOx for Improved Operation of Phase Change Random Access Memory

2005 ◽  
Vol 888 ◽  
Author(s):  
Jin-Seo Noh ◽  
Dong-Seok Suh ◽  
Sang Mock Lee ◽  
Kijoon H. P. Kim ◽  
Woong-Chul Shin ◽  
...  
Keyword(s):  
Room Temperature ◽  
Random Access ◽  
X Ray Diffraction ◽  
Access Memory ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Critical Requirement ◽  
Current Reduction ◽  
Microscopy Images

ABSTRACTConventional Ge2Sb2Te5 (GST) was modified by adding up a small amount of SiOx, using co-sputtering technique from multiple targets. The SiOx content was gradually increased by increasing the power applied to SiOx target, up to 8 volume percent. The sheet resistance of SiOx-containing GST exponentially increased, when the room-temperature-deposited samples were annealed at 300 °C. Transmission electron microscopy images revealed that no SiOx particulates were formed, which was confirmed by Gattan image filtering. It was indicated by x-ray diffraction patterns that the grain size of SiOx-containing GST is smaller than normal GST with lattice locally distorted at its crystalline state, suggesting that molecular SiOx is homogeneously distributed throughout the GST matrix. We observed that the crystallization temperature of SiOx-containing GST is gradually elevated by increasing the SiOx content, while the melting point decreased. These observations led to the reset current reduction, which is a critical requirement for the high density PRAM.

scholarly journals Effect of Zr4+ Content on Crystal Structure, Micromorphology and Dielectric Properties of Ba(Zrx Ti1-X)O3 Ceramics

2019 ◽  
Vol 3 (1) ◽  
Keyword(s):  
Crystal Structure ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Great Influence ◽  
Secondary Phase ◽  
Solid State Reaction Method ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

Ba(Zrx Ti1-x)O3 ceramics (X=1.5, 2.0, 2.5, 3.0) were prepared by solid-state reaction method. Effect of controlling the ratio of Zr/Ti on the crystal structure, micromorphology and dielectric properties of BZT ceramics. Their crystal structures, morphologies, and electric properties were respectively characterized using X-ray diffraction, scanning electron microscope and impedance analyzer. The X-ray diffraction patterns show that the zirconium titanate ceramic samples behave cubic phase structure and no secondary phase. The ratio of Zr/Ti has a great influence on the crystal structure, microstructure and dielectric properties. As the Zr4+ content increases, the lattice constant increases and the grain size decreases. The dielectric constant is the largest when the Zr content is 15%. As the Zr4+ content increases, the dielectric constant decreases gradually, and the Curie temperature moves toward the low temperature region.

Combustion Synthesis of Graphene from Waste Paper for High Performance Supercapacitor Electrodes

2017 ◽  
Vol 17 (01n02) ◽  
pp. 1760023 ◽  
Author(s):  
Dayakar Chowdary Singu ◽  
B. Joseph ◽  
V. Velmurugan ◽  
Syamsai Ravuri ◽  
A. Nirmala Grace
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Cost Effective ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Supercapacitor ◽  
Cost Effective Method ◽  
Discharge Duration ◽  
Graphene Paper ◽  
Supercapacitor Applications

Incessant streak of unsuccessful attempts to synthesize low cost graphene with larger flake size and purity is frequently reported. Any reported methods that result in few layers of graphene with minimal contamination are definitive to exist. In this work, graphene was prepared economically from source of “paper” and detailed investigation was done on the effect of synthesizing parameters like paper source, temperature and amount of urea in the formation of graphene. This is a cost effective method, in which the paper that we use in our daily life was carbonized with the help of urea at a temperature of 850[Formula: see text]C under N2 atmosphere. The paper source was varied, shape of the paper was altered and the graphene paper with large surface area was synthesized without smudging and the prepared graphene paper was analyzed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) for its structural, morphological investigation. To test the supercapacitance performance, electrochemical behavior was investigated in 6[Formula: see text]M KOH electrolyte. The specific capacitance of 1122[Formula: see text]F/g was obtained at 5[Formula: see text]mV/s scan rate. Chronopotentiometry curves showed an excellent cyclic stability with higher charge/discharge duration and hence could be used for electrochemical supercapacitor applications.

Facile Preparation of Cadmium Gallate Nanoparticles as a Novel Photocatalyst with High Efficiency and Stability

2019 ◽  
Vol 11 (5) ◽  
pp. 678-682
Author(s):  
Ce Liang ◽  
Nian Tao ◽  
Bowen Wang ◽  
Wenjun Liu ◽  
Ke Bi ◽  
...  
Keyword(s):  
High Efficiency ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Calcination Process ◽  
X Ray ◽  
Subsequent Calcination ◽  
Uv Visible ◽  
Diffraction Patterns ◽  
Performance Results ◽  
Microscopy Images

In this work, we introduced a facile approach for preparing cadmium gallate (CdGa2 O4 nanoparticles, and we first studied the photocatalytic properties of this ternary spinel oxide. Through a solvothermal process for the formation of precursor and the subsequent calcination process for recrystallization, CdGa2 O4 nanoparticles with diameter of ca. 12 nm were synthesized. They were characterized by using X-ray diffraction patterns and electron microscopy images. UV-visible diffuse absorption spectroscopy was also conducted; its spectra indicate that CdGa2 O4 nanoparticles have strong but small blue-shift absorption relative to that of the bulk samples. Moreover, the CdGa2 O4 nanoparticles could photocatalytically decompose rhodamine B (RhB) molecules with high efficiency in aqueous solution under ultraviolet irradiation. Notably, this novel photocatalyst exhibited outstanding recycling stability, and it retained almost the same capacity in the fourth photocatalytic cycle. We deduce that the high photocatalytic performance results from the large specific surface area, energetic photoinduced carriers, and inherent stability.

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