The effect of silver concentration and calcination temperature on structural and optical properties of ZnO:Ag nanoparticles

2015 ◽  
Vol 29 (01) ◽  
pp. 1450254 ◽  
Author(s):  
M. Shayani Rad ◽  
A. Kompany ◽  
A. Khorsand Zak ◽  
M. E. Abrishami
Keyword(s):  
Calcination Temperature ◽  
Sol Gel ◽  
Visible Emission ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Zno Nps ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Average Size

Pure and silver added zinc oxide nanoparticles ( ZnO -NPs and ZnO : Ag -NPs) were synthesized through a modified sol–gel method. The prepared samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. In the XRD patterns, silver diffracted peaks were also observed for the samples synthesized at different calcination temperatures of 500°C, 700°C, 900°C except 1100°C, in addition to ZnO . TEM images indicated that the average size of ZnO : Ag -NPs increases with the amount of Ag concentration. The PL spectra of the samples revealed that the increase of Ag concentration results in the increase of the visible emission intensity, whereas by increasing the calcination temperature the intensity of visible emission of the samples decreases.

Effect of fuel content on formation of zinc aluminate nano and micro-particles synthesised by high rate sol–gel autoignition of glycine-nitrates

2016 ◽  
Vol 70 (3) ◽  
Author(s):  
Shiva Salem
Keyword(s):  
Thermal Analyses ◽  
Sol Gel ◽  
High Rate ◽  
Zinc Aluminate ◽  
X Ray Diffraction ◽  
Micro Particles ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Average Size ◽  
20 Nm

AbstractThe autoignition technique using glycine as fuel and related nitrate salts as an oxidiser is able to produce zinc aluminate spinel. The precursors were synthesised with lean and rich fuel at pH of 7.0 and the materials so obtained were calcined at various temperatures ranging from 600-1200°C. The autoignition process of precursors was studied by the simultaneous thermo-gravimetric and differential thermal analyses to determine the ignition mechanism. The calcined powders were characterised by X-ray diffraction, Brunauer-Emmett-Teller technique and transmission electron microscopy. The product contains nano-sized particles with an average size of approximately 20 nm. The XRD patterns showed the formation of ZnO in the powder obtained by the fuel-rich precursor and calcined at 600°C which disappears at 800°C due to solid-state reaction and proper crystallisation after heat treatment. The results presented here can be useful in manufacturing nano and micro-sized ZnAl

The effects of different polymerization agents on structural and optical properties of (K0.5Na0.5)NbO3 nanopowders synthesized by a facile green route

2014 ◽  
Vol 28 (28) ◽  
pp. 1450224 ◽  
Author(s):  
Gh. H. Khorrami ◽  
A. Kompany ◽  
A. Khorsand Zak
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
Structural And Optical Properties ◽  
Transmission Electron ◽  
Green Route ◽  
Xrd Patterns ◽  
Average Size

( K 0.5 N 0.5) NbO 3 lead-free nanopowders were synthesized by a modified sol–gel method in different media: gelatin, starch and chitosan, as polymerization and stabilizer agents. The proper temperature needed for calcinating the prepared gel was obtained using thermogravometric analysis (TGA). Structural and optical properties of the prepared powders were investigated and compared using X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-Vis diffused reflectance spectroscopy. The XRD patterns of the synthesized samples confirmed the formation of the orthorhombic structure at 600°C calcination temperature with no remarkable extra peaks. TEM images showed that the morphologies of the particles prepared in the three different media are cubic with the average size of about 69, 34 and 49 nm for gelatin, starch and chitosan, respectively. The value of the energy band gap of the samples was calculated by diffused reflectance spectroscopy, using Kubelka–Munk method. Our results showed that the type of the polymerization agent is important in preparing KNN nanoparticles and affects the structural and optical properties of the synthesized samples.

Structural and optical properties of KNN nanocubes synthesized by a green route using gelatin

2015 ◽  
Vol 08 (02) ◽  
pp. 1550030 ◽  
Author(s):  
Gh. H. Khorrami ◽  
A. Kompany ◽  
A. Khorsand Zak
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Structural Deformation ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Transmission Electron ◽  
Green Route ◽  
Vis Spectroscopy ◽  
Xrd Patterns ◽  
Average Size

Sodium potassium niobate nanoparticles [( K 0.5 Na 0.5) NbO 3, KNN ], KNN-NPs, were synthesized using a modified sol–gel method. Structural and optical properties of the prepared samples were investigated by thermogravometric analyzer (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman and UV–Vis spectroscopy. The XRD patterns showed that the formation of the orthorhombic KNN-NPs starts at 500°C calcination temperature. Raman spectroscopy was used to investigate the crystalline symmetry and the structural deformation of the prepared KNN-NPs. TEM images showed that the morphology of the prepared particles is cubic, with the average size of about 50 nm. From diffused reflectance spectroscopy along with using Kubelka–Munk method, the energy bandgaps were determined to be indirect with the values of 3.13 eV and 3.19 eV for the samples calcined at 500°C and 600°C, respectively.

Preparation of Nanosized TiO2 Synthesized by Sol-Gel Pathway Using Ionic Liquid as Assistant and its Photocatalytic Activities

2012 ◽  
Vol 535-537 ◽  
pp. 2240-2244
Author(s):  
Wei Wei ◽  
Chang Shun Yu ◽  
Shao Jun Wang ◽  
Qing Da An
Keyword(s):  
Ionic Liquid ◽  
Diffuse Reflectance ◽  
Sol Gel ◽  
Rutile Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Average Size ◽  
Nanosized Tio2

Nanosized TiO2 particles were synthesized by sol-gel method using ionic liquid as assistant. The samples were characterized by UV-vis diffuse reflectance spectra, X-ray diffraction (XRD), transmission electron microscopy (TEM). It was shown that the phase detectable was mainly rutile phase with uniform sphericity and the average size was 10nm. Along with the rise of sintering temperature, grain diameter became bigger. The photocatalytic activities of nanosized TiO2 were evaluated by the reduction yield in the presence of CO2 and water. The result showed that TiO2 catalysts has efficient photocatalytic activities, of which made with [OMIM]BF4 displayed the highest photocatalytic active in the experiment.

Synthesis and Photocatalytic Properties of ZnO-Volcanics Composites

2013 ◽  
Vol 331 ◽  
pp. 497-502
Author(s):  
Ai Hua Wang ◽  
Ping Che ◽  
Jie Min Liu ◽  
Gui Hua Wang
Keyword(s):  
Calcination Temperature ◽  
Physical Adsorption ◽  
Sol Gel ◽  
Degradation Efficiency ◽  
X Ray Diffraction ◽  
Photocatalytic Reactor ◽  
Decolorization Rate ◽  
Surface Areas ◽  
Transmission Electron ◽  
Average Grain Size

in this paper, nano-ZnO were synthesized via a sol-gel method, and ZnO-volcanics composites (ZVCs) were prepared via physical adsorption process. The morphology and structure of ZnO/ ZnO-volcanics composites (ZVCs) samples were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM).BET surface areas of the catalysts were determined by N2 adsorption (BET). According the data of XRD, the average grain size of ZnO is 15.1 nm consistent with the result observed by TEM (16.3 nm). Photocatalytic performance of ZnO and ZVCs were carried out in sprinkling photocatalytic reactor, with methylene blue (MB) as pollutants model. Decolorization rate is select as the evaluation parameters for the degradation effect. The effect of catalyst dosage, MB initial concentration, calcination temperature and pH on the degradation efficiency have been investigated. The MB degradation efficiency was 99.2% when the concentration of MB, the ZVCs, the pH and the calcination temperature were 10 mg/L, 20 g/L, and 10.03, 500 oC respectively. In the catalysts recycle experiments, the decolorization rate of MB using ZVCs is 90.2% after utilization for six times, overwhelmingly higher than that of ZnO (22.6%), indicating immobilization is efficient.

Homogeneity in the Polyether Alkoxide Sol‐Gel Synthesis of YBa2Cu3O7-δ

1994 ◽  
Vol 346 ◽  
Author(s):  
Carol S. Houk ◽  
Gary A. Burgoine ◽  
Catherine J. Page
Keyword(s):  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Mapping Techniques ◽  
Starting Solutions ◽  
Average Size ◽  
Sol Gel Synthesis ◽  
Elemental Maps

ABSTRACTWe have investigated the homogeneity of sol‐gel derived YBa2Cu307‐s from the solution phase to the final product using transmission electron microscopy (TEM), x‐ray diffraction (XRD), and Energy Dispersive X‐ray (EDX) lateral mapping techniques. The starting solutions contain stoichiometric amounts of the metal 2‐(2‐methoxyethoxy)ethoxide components in 2‐(2‐methoxyethoxy)ethanol and appear to be homogeneous by TEM with a uniform distribution of particles having an average size of less than 40 â. Through elemental mapping we see elemental segregation in the high temperature (950 °C) products, which are orthorhombic by XRD. In elemental maps of gel samples fired to 700 °C, which are tetragonal by XRD, we also see elemental inhomogeneity within particles and phase zoning in maps of products from finely ground gels. A comparison of elemental maps and x‐ray diffraction patterns of the products from gel processing and conventional solid state processing is made.

Preparation of ZnO@void@SiO2 Rattle Type Core–Shell Nanoparticles via Layer-by-Layer Method

NANO ◽  
2016 ◽  
Vol 11 (09) ◽  
pp. 1650103 ◽  
Author(s):  
Xiaoman Wang ◽  
Junda Song ◽  
Hongling Chen
Keyword(s):  
Sol Gel ◽  
Carbon Layer ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
Hexagonal Wurtzite Crystal Structure ◽  
Transmission Electron ◽  
Measurement Results ◽  
Average Size ◽  
Core Shell Nanoparticles

In this paper, we prepared the rattle type nanoparticles ZnO@void@SiO2 by two successive coating processes, followed by heat treatment. The carbon layer was formed over ZnO surface with the aid of the hydrothermal treatment of glucose. Then the resulting composite was used to fabricate a silica shell on the surface by sol–gel method. Finally, ZnO particles were released but still trapped inside the silica hollow after calcination, that is, ZnO@void@SiO2. The composites were characterized by scanning and transmission electron microscope, N2 adsorption experiment, X-ray diffraction, Fourier transform infrared spectroscopy and UV-Vis absorption spectra. The rattle type structure was conformed and the sphere-like structure with the average size of 70 nm and hexagonal wurtzite crystal structure were also observed. The measurement results of optical properties showed even though ZnO@C@SiO2 presented no photocatalysis, ZnO@void@SiO2 showed high activity even the ZnO core was encapsulated with the SiO2 hollow.

Improvement of the Crystallinity of La2CuO4 Nanoparticles Using the Vacuum Treatment

2021 ◽  
Vol 1028 ◽  
pp. 44-49
Author(s):  
Anita Eka Putri ◽  
Suci Winarsih ◽  
Budhy Kurniawan ◽  
Dicky Rezky Munazat ◽  
Dhawud Sabilur Razaq ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Vacuum Treatment ◽  
Vacuum Pressure ◽  
Morphological Properties ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Xrd Patterns

Nanoparticles of La2CuO4 (LCO) with different particles and crystallite size have been synthesized by the sol-gel method. The samples have been sintered at 600, 650, and 700°C. The sintering process have been performed in atmospheric pressure and vacuum pressure. The structural and morphological properties of the samples have been investigated by the X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM). The XRD patterns of the samples have shown that all samples crystallize in orthorhombic structure with Bmab space group. Additionally, Rietveld refinement process have shown that higher sintering temperature, as well sintering process under vacuum pressure, can improve both phase purity and the crystallinity of the samples. SEM and TEM results have also shown that higher sintering temperature results in a sample with larger particle size.

scholarly journals Synthesis of Flower-Like Cu2ZnSnS4Nanoflakes via a Microwave-Assisted Solvothermal Route

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Fei Long ◽  
Shuyi Mo ◽  
Yan Zeng ◽  
Shangsen Chi ◽  
Zhengguang Zou
Keyword(s):  
Electron Microscopy ◽  
Raman Scattering ◽  
Zinc Acetate Dihydrate ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Direct Band ◽  
Xrd Patterns ◽  
Average Size

Flower-like Cu2ZnSnS4(CZTS) nanoflakes were synthesized by a facile and fast one-pot solution reaction using copper(II) acetate monohydrate, zinc acetate dihydrate, tin(IV) chloride pentahydrate, and thiourea as starting materials. The as-synthesized samples were characterized by X-ray diffraction (XRD), Raman scattering analysis, field emission scanning electron microscopy (FESEM) equipped with an energy dispersion X-ray spectrometer (EDS), transmission electron microscopy (TEM), and UV-Vis absorption spectra. The XRD patterns shown that the as-synthesized particles were kesterite CZTS and Raman scattering analysis and EDS confirmed that kesterite CZTS was the only phase of product. The results of FESEM and TEM show that the as-synthesized particles were flower-like morphology with the average size of 1~2 μm which are composed of 50 nm thick nanoflakes. UV-Vis absorption spectrum revealed CZTS nanoflakes with a direct band gap of 1.52 eV.

Synthesis and Characterization Silver, Zinc Oxide and Hybrid Silver/Zinc Oxide Nanoparticles for Antimicrobial Applications

Nano LIFE ◽  
2014 ◽  
Vol 04 (01) ◽  
pp. 1440003 ◽  
Author(s):  
Myisha Roberson ◽  
Vijaya Rangari ◽  
Shaik Jeelani ◽  
Temesgen Samuel ◽  
Clayton Yates
Keyword(s):  
Zinc Oxide ◽  
Zno Nanoparticles ◽  
Biomedical Application ◽  
Fungal Growth ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Zno Nps ◽  
E Coli ◽  
Transmission Electron ◽  
20 Nm

Silver ( Ag ) and zinc oxide ( ZnO ) are well known for both antimicrobial and pro-healing properties. Here, we present a novel method to synthesize Ag and ZnO nanoparticles (NPs), as well as hybrid Ag / ZnO NPs using a custom, temperature controlled microwave assisted technique. Microwave synthesis has been shown not only to enhance the rate of chemical reactions, but also in some cases to give higher product yields over thermal heating. The as-synthesized NPs were characterized by X-ray diffraction (XRD) to study the crystalline structure, composition and purity. Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) was used to study particle size, shape, composition and morphology. These results indicated that the as-prepared Ag NPs are spherical in shape and ~ 20 nm in sizes. The ZnO NPs are typically rod shaped and the particle sizes are ~ 20 nm in width and 100 nm in length. These NPs were tested for antibacterial and/or antifungal properties using disc diffusion assays. Results show microwave synthesized NPs inhibit growth of S. aureus, E. coli and C. albicans at 50 μ g/mL treatment concentration. Ag NPs were most effective in inhibiting bacterial and fungal growth at the concentrations tested followed by hybrid Ag / ZnO and ZnO nanoparticles. These results also suggest that the hybridization of ZnO to Ag NPs may reduce the toxicity of Ag NPs. Further studies are needed to understand the functional interaction between the two types of NPs and to improve their ability for biological or biomedical application.

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