Effect of Laser Energy on Optical and Morphological Properties of Gold Nanoparticles

2020 ◽  
Vol 12 (7) ◽  
pp. 989-993
Author(s):  
Kahtan A. Mohammed ◽  
Azhar A. Habieb ◽  
Ahmed O. Swary ◽  
Dalal N. Ahilfi ◽  
Dalal K. Thbayh
Keyword(s):  
Noble Metals ◽  
Room Temperature ◽  
Laser Energy ◽  
Gold Foil ◽  
Morphological Properties ◽  
Visible Spectroscopy ◽  
Atomic Force ◽  
Liquid Depth ◽  
Gold Nps ◽  
Uv Visible

Noble metals gold NPs are produced by pulsed (“Q-switched, 1064 nm Nd: YAG”) ablation of gold foil dipped in doubles distilled water DDW by laser. (PLAL) the process was performed with laser energy in range (400–700) mJ at (90 pulses, wavelength 1064 and room temperature and liquid depth 9 mm. The influence of laser energies have been tested structurally, optically and morphologically and examined by using scanning electron microscope (SEM), UV-visible spectroscopy and atomic force microscope (AFM). The absorption spectra of AuNPs are prepared in water piercing and solitary peaks nearby 518 and 524 nm, demonstrating the assembly of clean and sphericals in shape AuNPs with the middling size in the range of (20–50) nm. SEM and AFM have established all the measurements of size.

Synthesis and Characterization of Gold Nanoparticles Synthesized in Gel and Paper by Electrolysis

2019 ◽  
Vol 824 ◽  
pp. 163-167
Author(s):  
Pema Dechen ◽  
Ekasith Somsook
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gold Nanoparticles ◽  
Room Temperature ◽  
Synthesis And Characterization ◽  
Visible Spectroscopy ◽  
Gold Leaf ◽  
Uv Visible ◽  
Scanning Electron

In this report, synthesis and characterization of gold nanoparticles (AuNPs) from gold leaf by electrolysis in two different media (gel and paper) in presence of sodium chloride (NaCl), glucose (C6H12O6) and polyvinyl pyrrolidone (PVP) at room temperature were investigated. Graphite was used as two electrodes, NaCl was used as an electrolyte, C6H12O6 was used as reducing agent and PVP was used as stabilizer to control the aggregation of the nanoparticles. UV-Visible spectroscopy (UV-Vis) and scanning electron microscopy (SEM) were used to confirm the characteristics and morphologies of the synthesized AuNPs.

scholarly journals Mild and Efficient Tunable Brønsted Acidic Ionic Liquid Catalyzed O-Acetylation and O-Trimethylsilylation with Trimethylsilyl Acetate (TMSOAc) and Hexamethyldisilazane (HMDS)

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 825
Author(s):  
Amit Ravindra Pantawane ◽  
Mayur Thul ◽  
Yi-Jyun Lin ◽  
Michelle Lin ◽  
Wesley Lin ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Room Temperature ◽  
Visible Spectroscopy ◽  
Acidic Ionic Liquid ◽  
Post Process ◽  
Brønsted Acidic Ionic Liquid ◽  
Acidic Ionic Liquids ◽  
Uv Visible ◽  
Work Up

This report discloses a mild and efficient O-acetylation using easily accessible TMSOAc as a novel acetyl reagent and O-trimethylsilylation using HMDS for various alcohols catalyzed by tunable Brønsted acidic ionic liquids (TBAILs). Imidazolium-based TBAILs were prepared by a two-step atom-economic reaction and acidities measured by using UV-visible spectroscopy. Both protections for alcohols were accomplished at room temperature with good to excellent yields, while the products and TBAILs were separated by simple work-up for O-silylation and column chromatography for O-acetylation. Notably, with the simple post-process, TBAILs catalyst in this solvent free method easily recovered and recycled several times without significant degradation.

Preparation of Green Nanosilver by Ascorbic Acid and its Spectral Properties

2013 ◽  
Vol 749 ◽  
pp. 503-506
Author(s):  
Yang He Luo ◽  
Chun Ming Wang ◽  
Wen Qing Yin ◽  
Ai Hui Liang
Keyword(s):  
Ascorbic Acid ◽  
Spectral Properties ◽  
Room Temperature ◽  
Rayleigh Scattering ◽  
Resonance Rayleigh Scattering ◽  
Visible Spectroscopy ◽  
Laser Scattering ◽  
Transmission Electron ◽  
Uv Visible ◽  
Strong Absorption Peak

In the presence of stabilizer of citrate and room temperature, stable green nanosilver sol was prepared by reduction of AgNO3by ascorbic acid. It was characterized by UV-visible spectroscopy, resonance Rayleigh scattering (RRS) spectroscopy, laser scattering and transmission electron microscopy. Results showed that the nanosilver sol exhibited a RRS peak at 496 nm, a strong absorption peak at 414 nm and the particle size is 12 nm.

scholarly journals Analysis and characterisation of anthocyanins in mulberry fruit

2010 ◽  
Vol 28 (No. 2) ◽  
pp. 117-126 ◽  
Author(s):  
C. Qin ◽  
Y. Li ◽  
W. Niu ◽  
Y. Ding ◽  
R. Zhang ◽  
...  
Keyword(s):  
Food Processing ◽  
Room Temperature ◽  
Morus Alba ◽  
Visible Spectroscopy ◽  
Fruit Extract ◽  
Mulberry Fruit ◽  
Medicinal Food ◽  
Uv Visible ◽  
Mulberry Fruits

The fruit of mulberry (<I>Morus alba</I> L., Moraceae) has been used as medicinal food in China for a long history. The pigment from the fruit extract is a kind of natural colourant for food processing and has potential medical and commercial values. This study focuses on the analysis and characterisation of anthocyanins from mulberry pigment. The fresh mulberry fruits were extracted with the solvent of 95% alcohol/0.1% HC l (1:1, ratio) at room temperature for 4 h in the dark. After the isolation using C-18 column, the pigment was identified with UV-Visible Spectroscopy, HPLC-PAD, LC-MS, and <SUP>1</SUP>HNMR. The results showed that the abundant anthocyanins in mulberry pigment are cyanidin 3-<I>O</I>-rutinoside (60%) and cyanidin 3-<I>O</I>-glucoside (38%). The minor anthocyanins (totally 2%) are pelargonidin 3-<I>O</I>-glucoside and pelargonidin 3-<I>O</I>-rutinoside.

Photoreactive Carbon and Nitrogen-Codoped ZnWO4 Nanoparticles: Synthesis and Reactivity

2012 ◽  
Vol 621 ◽  
pp. 172-177 ◽  
Author(s):  
Su Hua Chen ◽  
Bi Xuan Wang ◽  
Xian Hua Qiu ◽  
Zhen Sheng Xiong
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Region ◽  
Weight Ratio ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Carbon And Nitrogen ◽  
Uv Visible

In order to improve ZnWO4 photocatalytic activity under visible light, the C, N-codoped ZnWO4 nanoparticles have been successfully synthesized by choosing C3N4 generated from tripolycyanamide pyrolysis as the source of Carbon and Nitrogen and the influence of C3N4 concentration on structural, optical and morphological properties of C, N-codoped ZnWO4 using X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscopy (SEM) and photocatalytic decoloration of rhodamine B (RhB) aqueous solution under visible light. It was found that the presence of carbon and nitrogen could not improve the crystallization of ZnWO4 species but could enhance their photoabsorption property in the visible region. The results also showed that the photocatalytic activity of the as-prepared ZnWO4 is higher than that of pure ZnWO4 with the optimum effect occurring at RC3N4 = 9 % (the weight ratio of tripolycyanamide to ZnWO4)

Investigation of Optical Properties of ZnO/MnO2, ZnO/TiO2 and ZnO/MnO2/TiO2 Nanocomposites

2014 ◽  
Vol 938 ◽  
pp. 123-127 ◽  
Author(s):  
G. Shanmuganathan ◽  
I.B. Shameem Banu
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Energy Gap ◽  
Visible Region ◽  
Solid State Reaction Method ◽  
Morphological Properties ◽  
Energy Dispersive Analysis ◽  
Reaction Method ◽  
Uv Visible

ZnO nanocomposites such as (ZnO)0.8(MnO2)0.2, (ZnO)0.8(TiO2)0.2and (ZnO)0.8(MnO2)0.1(TiO2)0.1were prepared by solid state reaction method at room temperature. The structural analysis was carried out with help of powder XRD to confirm the formation of the composites. The morphological properties and presence of elemental compositions were analyzed with scanning electron microscope and energy dispersive analysis spectroscopy respectively. Optical properties were studied with UV visible spectrophotometer. From the transmittance spectrum, it is concluded that the synthesized composite materials have the transmittance in the range of 80 to 95% in the visible region. The calculated optical band gap values for pure ZnO is 3.16 eV and the values are 3.7eV, 5.27eV and 4.46eV for the composites ZnO/MnO2, ZnO/TiO2and ZnO/MnO2/TiO2, respectively. The study has found that the ZnO/MnO2, ZnO/TiO2and ZnO/MnO2/TiO2composites have very large energy gap as that of insulator.

Low-temperature kinetic measurements of microsecond freeze–hyperquench (MHQ) cytochrome oxidase monitored by UV–visible spectroscopy with a newly designed cuvette

2006 ◽  
Vol 34 (1) ◽  
pp. 136-138 ◽  
Author(s):  
F.G.M. Wiertz ◽  
S. de Vries
Keyword(s):  
Low Temperature ◽  
Cytochrome Oxidase ◽  
Cytochrome C Oxidase ◽  
Room Temperature ◽  
Paracoccus Denitrificans ◽  
Visible Spectroscopy ◽  
Kinetic Measurements ◽  
Intermediate States ◽  
Powder Samples ◽  
Uv Visible

A special cuvette was designed to measure optical changes of MHQ (microsecond freeze–hyperquench) powder samples [Wiertz, Richter, Cherepanov, MacMillan, Ludwig and de Vries (2004) FEBS Lett. 575, 127–130] at temperatures below approx. 250 K. Reduced cytochrome c oxidase from Paracoccus denitrificans was reacted with O2 for 100 μs, frozen as a powder and transferred to the cuvette. Subsequently, cytochrome oxidase was allowed to react further following stepwise increments of the temperature from 100 K up to 250 K while recording spectra between 300 and 700 nm. The temperature was raised only when no further changes in the spectra could be detected. The experiment yielded spectra of the A, PM, F and O intermediate states. This demonstrated that the catalytic cycle of cytochrome oxidase at low temperature is similar to that at room temperature and so verifies the suitability of this method for the study of enzymes with high catalytic-centre activity.

scholarly journals Congo Red and Nigrosine Dye Degradation using Dimethyl Dioxirane as an Oxidising Agent

2021 ◽  
Vol 37 (5) ◽  
pp. 1221-1228
Author(s):  
S. Vinotha ◽  
A.Leema Rose
Keyword(s):  
Congo Red ◽  
Room Temperature ◽  
Functional Group ◽  
Dye Degradation ◽  
Visible Spectroscopy ◽  
Before And After ◽  
Ft Ir ◽  
Combined Action ◽  
Uv Visible ◽  
Ft Ir Spectroscopy

The advanced oxidation of Congo red (CR) and Nigrosine (NI) using the combined action of dimethyl dioxirane as an oxidising agent is described in this study. The effects of several parameters, such as the concentration of the oxidising agent, the initial dye concentration, and the pH, have been investigated. At room temperature, the oxidising agent dimethyl dioxirane was employed to test the degradation of CR and NI dyes. On the degradation efficiency of CR and NI, pH’s effects, oxidising agent, and initial dye concentration were examined. The absorbance of CR and NI dyes before and after degradation was measured using UV-visible spectroscopy. The functional group existing in the dyes before and after degradation was determined using FT-IR spectroscopy.

scholarly journals Synthesis, characterization, electrochemical studies and X-ray structures of mixed-ligand polypyridyl copper(II) complexes with the acetate

2016 ◽  
Vol 81 (11) ◽  
pp. 1251-1262 ◽  
Author(s):  
Oluwafunmilayo Adekunle ◽  
Ray Butcher ◽  
Oladapo Bakare ◽  
Olusegun Odunola
Keyword(s):  
Room Temperature ◽  
Magnetic Measurements ◽  
Magnetic Moments ◽  
Copper Ion ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Elemental Analyses ◽  
Structural Details ◽  
Uv Visible

[Cu(phen)2(CH3COO)](ClO4).2H2O (1) and [Cu(bipy)2(CH3COO)]-(ClO4).H2O (2) {phen = 1,10-phenanthroline, bipy = 2,2?-bipyridine}were synthesized and characterized. The complexes were characterized by employying elemental analyses, infrared and UV-Visible spectroscopy, room temperature magnetic measurements and the crystal structures elucidated using X-ray diffraction experiment. The redox properties of the complexes were also investigated. Both structures have a square pyramidal CuN4O chromophore which exhibit significant distortions due to long Cu-O [2.217(3) ? for (1) and 2.179 (1) for (2)] and Cu-N [2.631(2) ? for (1) and 2.714(1) ? for (2)] bonds. This distortion if further shown by the O-Cu-N bond angles [147.71(8) o for (1) and 153.40(5) o for (2)]. The elemental analyses further support the structural details unveiled by the single crystal X-ray diffraction analysis. The infrared spectra shows the acetate vibrational frequencies at 1587 cm-1,1428 cm-1, 1314 cm-1 for (1) and 1571 cm-1, 1441 cm-1, 1319c m-1 for (2) and the perchlo-rate bands at 1059 cm-1, 720 cm-1 (1) and 1080 cm-1,768 cm-1 (2). The broad d-d bands for the copper ion at 14,514 cm-1(1) and 14,535 cm-1(2) support the adoption of square pyramid geometries. The magnetic moments for the two complexes are 1.83 B.M for (1) and 1.72 B.M for (2). The peak to peak values of the two complexes show that the electrode reactions are quasi-reversibile with ?Ep = 0.023V (1) and 0.025V for (2). In both structures, there are ?-? intermolecular interactions in addition to hydrogen bonding between the units.

Room-temperature and flexible PEDOT:PSS–WO3 gas sensor for nitrogen dioxide detection

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940013
Author(s):  
Swapnil Shinde ◽  
Chang-Yuan Jiang ◽  
Cheng-Xuan Zheng ◽  
Yi-Zhen Wang ◽  
Keh-Moh Lin ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Gas Sensor ◽  
Room Temperature ◽  
Response Rate ◽  
Morphological Properties ◽  
Bending Tests ◽  
Uv Visible ◽  
Text Content ◽  
Fabrication Parameters ◽  
Sensing Performance

In this paper, a resistance type gas sensor which consists of tungsten oxide (PEDOT:PSS), [Formula: see text] particles and silver finger electrodes was prepared on glass as well as (PET) substrates. The structural and surface morphological properties of the sensors were studied using (XRD), UV-visible, (FTIR), (FE-SEM) and 3D optical microscopy. The influence of fabrication parameters on the sensibility for nitrogen dioxide [Formula: see text] detection is discussed. Experimental results reveal that the sensor with [Formula: see text] content of 2 g/mL shows the highest response rate of 2.31 with increasing concentration up to 80 ppm of nitrogen dioxide gas. The response of the flexible gas sensor reveals improved sensing performance after 500 bending tests.

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