scholarly journals Variation of Alkali Concentration and Temperature: Its Effect on the Morphology of ZnO Nanoparticles Synthesized via Solvothermal Technique

2021 ◽  
Vol 411 ◽  
pp. 3-15
Author(s):  
Boon Siong Wee ◽  
Eric Kwabena Droepenu ◽  
Suk Fun Chin ◽  
Kuan Ying Kok ◽  
Woei Ting
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Average Particle Size ◽  
Alkali Concentration ◽  
Average Particle ◽  
Zno Nanostructures ◽  
Tem Analysis ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Concentration Ratios

This study reports on synthesis of ZnO nanostructures using Zinc chloride (ZnCl2) as precursors and Potassium hydroxide (KOH) as alkaline source in a solvothermal process with varying molar concentrations (Zn2+/OH-) of 1:1, 1:3 and 1:5 for temperatures of 30 °C and 50 °C. The synthesized nanostructures were characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FT-IR) Spectroscopy, and Ultraviolet Visible (UV-Vis) spectroscopy. ZnO nanostructures synthesized at lower ratios (1:1) exhibited wurtzite hexagonal shapes. However, as the concentration ratios increases in both cases, spherical structures were formed with the emergence of some rod-like structures dominating, and finally aggregated to form flower-like structures at 30 °C temperature. The average crystallite size for nanostructures from XRD (30-50 °C) were in the range 15-21 nm whereas the average particle size from TEM analysis (30-50 °C) were in the range 39-76 nm. Increase in temperature and molar concentration of the alkaline source generally decreased the crystallite and particle size of the as well as a decrease in the wavelength of ZnO nanostructures as a result of blue-shifting of the absorption peak. FT-IR spectra of ZnO NSs prepared from concentration ratios of Zn2+: OH- (1:1, 1:3 and 1:5) at 30 °C and 50 °C showed characteristic peak bands at 461-467 cm-1 and 460-462 cm-1 respectively.

The Aggregation Study and Characterization of Silver Nanoparticles

2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Average Particle Size ◽  
Average Particle ◽  
Transmission Electron ◽  
Vis Spectroscopy

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.

Synthesis and Characterization of Water-Soluble Monolayer-Protected Gold Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Transmission Electron

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

Biosynthesis and Characterization of Copper Nanoparticles Using a Bioflocculant Extracted from Alcaligenis faecalis HCB2

2019 ◽  
Vol 11 (11) ◽  
pp. 1064-1070 ◽  
Author(s):  
Nkosinathi G. Dlamini ◽  
Albertus K. Basson ◽  
V. S. R. Rajasekhar Pullabhotla
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Copper Nanoparticles ◽  
Average Particle Size ◽  
Thermo Gravimetric Analysis ◽  
Average Particle ◽  
Gravimetric Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir

Bioflocculant from Alcaligenis faecalis HCB2 was used in the eco-friendly synthesis of the copper nanoparticles. Nanoparticles were characterized using a scanning electron microscope (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, thermo gravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FT-IR). The transmission electron microscopy images showed close to spherical shapes with an average particle size of ∼53 nm. Energy-dispersive X-ray spectroscopy analysis confirmed the presence of the Cu nanopartilces and also the other elements such as O, C, P, Ca, Cl, Na, K, Mg, and S originated from the bioflocculant. FT-IR results showed the presence of the –OH and –NH2 groups, aliphatic bonds, amide and Cu–O bonds. Powder X-ray diffraction peaks confirmed the presence of (111) and (220) planes of fcc structure at 2 of 33° and 47° respectively with no other impurity peaks.

scholarly journals Biosynthesis of Gold Nanoparticles by Essential Oil of Diplotaxis Acris Characterization and Antimicrobial Activities

2021 ◽  
Vol 37 (2) ◽  
pp. 405-412
Author(s):  
Mohamed Habib Oueslati ◽  
Lotfi Ben Tahar ◽  
A. Khuzaim Alzahrani ◽  
Jamith Basha ◽  
Omar H. Abd Elkader
Keyword(s):  
Essential Oil ◽  
Average Particle Size ◽  
Antimicrobial Activities ◽  
Nano Particles ◽  
Average Particle ◽  
Tem Analysis ◽  
Stabilizing Agents ◽  
E Coli ◽  
Ft Ir ◽  
Plausible Scheme

The present work reports a green biosynthesis of gold nano particles (EO-AuNPs) using an essential oil (EO) as a reducing agent of the Au(III) in HAuCl4. The EO was extracted by hydro-distillation from Diplotaxis acris flowers. A total of 16 compounds were detected from the EO oil by using GC–MS and 5-methylsulfanylpentanenitrile was identified as the major component (73.60 %). The biosynthesized EO-AuNPs were characterized performing UV–Vis, IR,XRD and TEM analyses.The UV-Vis revealed the typical features of surface plasmon resonance (SPR) of AuNPs at ~526 nm. The FT-IR spectrum of the biosynthesized nano particles exhibited the features of the nitrile (-C≡N) functional group indicating that the -C≡N-bearing EO components are likely acting as reducing and stabilizing agents for the formation of EO-AuNPs. The plausible scheme of EO-AuNPsformation was proposed.The TEM analysis showed that the EO- AuNPs were almost spherical in shape with an average particle size of 12.7 nm. In addition, the antimicrobial activity was carried out by diffusion of agar wells method. The results proved that the EO-AuNPs displayed a potential antimicrobial against gram negative strains, with a maximum zone of inhibition of 16 mm for E. coli at a concentration of 100 µg / ml.

scholarly journals Synthesis and Characterization of Surfactant Capped Copper Nanoparticles Using Natural Vitamin

2020 ◽  
Vol 32 (9) ◽  
pp. 2130-2134
Author(s):  
B. VARUN KUMAR ◽  
Y. PARVEEN TAJ ◽  
K. HUSSAIN REDDY
Keyword(s):  
Vitamin C ◽  
Copper Nanoparticles ◽  
Average Particle Size ◽  
Inert Gas ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Gas Insulation ◽  
Triton X

Copper nanoparticles (CuNPs) have captivated amazing and renewable interest in recent years due to their fascinating features. In present investigation, CuNPs were produced by reducing copper sulphate with ascorbic acid (vitamin C) in aqueous medium without inert gas insulation at low temperature (80 ºC). In present synthetic procedure, a native vitamin C was applied as insulating agent to prevent oxidation of nascent CuNPs during the process and in storage. Triton X-100 was added that worked both as a size controller and as a capping agent. The CuNPs were characterized by UV-visible and FT-IR spectroscopies, powder X-ray diffraction (PXRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX). Optical properties of Cu nanoparticles were explored using UV-vis spectroscopy. FT IR was employed to uncover the bonding between copper nanoparticles and Triton X-100. The CuNPs were discerned by PXRD and SEM-EDX Techniques. From the major diffraction peaks, the average particle size is determined using Debye-Scherer equation and it is found to be about 15 nm. It is hoped that the present results would pave a way for developing plans for the production of nascent CuNPs in the absence of inert gas insulation.

Analysis of the Promoter-Catalyst interaction between Mn and Rh by Transmission Electron Microscopy

2014 ◽  
Vol 7 (1) ◽  
Author(s):  
B. Graham ◽  
R.F. Klie
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Average Particle Size ◽  
Lattice Parameter ◽  
Average Particle ◽  
Fischer Tropsch ◽  
Transmission Electron ◽  
Three Samples ◽  
Promoter Interaction

In the hope of optimizing the Fischer-Tropsch mechanism to produce cleaner ethanol, the catalyst- promoter interaction between rhodium and manganese was examined by transmission electron microscopy. Three samples were analyzed on a carbon nanotube (CNT) substrate with 3 wt% rhodium (3%Rh/CNT), 1% manganese with 3 wt% rhodium (1%Mn/3% Rh/CNT), and 2% manganese with 3 wt% rhodium (2% Mn/3% Rh/CNT). The average particle size were found to be (1.9 ± 0.6) nm, (2.1 ± 0.5) nm, and (3.2 ± 0.6) nm, respectively. An increase in particle size indicates that the rhodium and manganese are interacting. The lattice parameter for rhodium were also determined to be (4.1 ± 0.1) Å, (4.2 ± 0.1) Å, and (3.8 ± 0.1) Å, respectively. The decrease in lattice parameter in the 2%Mn/3%Rh/CNT sample was most likely due to a change in the crystal structure of the rhodium particles as a result of the interaction between the manganese and rhodium.

scholarly journals Preparation and Characterization of Ultra-Fine Oil Palm Ash Powder by Ultrasonication and Alkaline Treatment for Its Evaluation as Reinforcing Filler in Natural Rubber

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 100
Author(s):  
Methakarn Jarnthong ◽  
Chutarat Malawet ◽  
Lusheng Liao ◽  
Puwang Li ◽  
Zheng Peng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Natural Rubber ◽  
Oil Palm ◽  
Average Particle Size ◽  
Alkaline Treatment ◽  
Bet Surface Area ◽  
Average Particle ◽  
Naoh Solution ◽  
Oil Palm Ash

Ultra-fine oil palm ash (OPA) particles were successfully prepared using ultrasonication along with optimal chemical deagglomeration. The influence of chemical treatment by sodium hydroxide (NaOH) solution on the OPA particles was found to be an important factor in enhancing deagglomeration efficiency. The average particle size of the original OPA (41.651 μm) decreased remarkably more than 130 times (0.318 μm) with an obvious increase of Brunauer–Emmet–Teller (BET) surface area after treating the OPA with 3M NaOH, followed by ultrasonication for 30 min. The changes in particle size and surface morphology were investigated using transmission electron microscopy and scanning electron microscopy. Moreover, the chemical functional groups of the untreated and treated OPA showed different patterns of infrared spectra by the presence of sodium carbonate species owing to the effect of NaOH treatment. The incorporation of both untreated and treated OPA in natural rubber by increasing their loading can improve cure characteristics (i.e., reducing optimum cure time and increasing torques) and cure kinetic parameters (i.e., increasing the rate of cure and reducing activation energy). Nevertheless, the strength, degree of reinforcement, and thermal stability of treated OPA as well as wettability between treated OPA particles and NR were greater than that resulting from the untreated OPA.

Synthesis of Dispersed Y2O3 Nanopowder from Yttrium Stearate

2013 ◽  
Vol 544 ◽  
pp. 3-7 ◽  
Author(s):  
Jin Sheng Li ◽  
Xu Dong Sun ◽  
Shao Hong Liu ◽  
Di Huo ◽  
Xiao Dong Li ◽  
...  
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Average Particle Size ◽  
Ceramic Materials ◽  
Average Particle ◽  
Water Medium ◽  
Nitrate Hexahydrate ◽  
Yttrium Nitrate ◽  
Ft Ir ◽  
Yttrium Nitrate Hexahydrate

Fine yttrium stearate powder was produced at a relatively low temperature using yttrium nitrate hexahydrate, ammonia and stearic acid as the raw materials. Dispersed Y2O3 nanopowder was synthesized by calcining the yttrium stearate. The formation mechanism of the precursor and the Y2O3 nanopowder was studied by means of XRD, TG-DTA, FT-IR, BET, FE-SEM and HR-TEM. Pure and dispersed Y2O3 nanopowder with an average particle size of 30 nm was produced by calcining the precursor at 600 °C. The particle size increases to about 60 nm with the increase of the calcination temperature to 1000 °C. In the preparation of Y2O3 from yttrium stearate, no water medium is involved, thus capillarity force and bridging of adjacent particles by hydrogen bonds can be avoided, resulting in good dispersion of the particles. The dispersed Y2O3 nanopowder prepared in this work has potential application in phosphors and transparent ceramic materials.

Sulfur Nanoparticles Synthesis and Characterization from H2S Gas, Using Novel Biodegradable Iron Chelates in Aqueous Surfactant Systems

2008 ◽  
Vol 1103 ◽  
Author(s):  
Aniruddha Subhash Deshpande ◽  
Ramdas B. Khomane ◽  
Bhalchandra K. Vaidya ◽  
Renuka M. Joshi ◽  
Arti S. Harle ◽  
...  
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Tween 80 ◽  
Average Particle ◽  
Iron Chelates ◽  
Ambient Conditions ◽  
Tem Analysis ◽  
Surfactant System ◽  
Surfactant Systems ◽  
Sulfur Nanoparticles

AbstractSulfur nanoparticles were synthesized from hazardous H2S gas by desulfurization based on liquid redox process [1]. The use of novel biodegradable iron chelates, in particular, FeCl3-malic acid chelate system has been extensively studied in various aqueous surfactant systems of Tween 80, SDS, CTAB for catalytic oxidation of H2S gas at ambient conditions of temperature, pressure and neutral pH. The structural features of sulfur nanoparticles have been characterized by XRD, TEM, and DLS measurements. XRD analysis indicates the presence of Metal-sulfur (JCPDS-08247). TEM analysis shows that the morphology of sulfur nanoparticles synthesized in aqueous surfactant system of Tween 80 is nearly uniform in size of 12nm average particle size, in SDS surfactant system shows 15nm average particle size, where as sulfur nanoparticles synthesized in CTAB shows average particle size of 7nm. The DLS result shows the mono-dispersity of the sulfur nanoparticles in the aqueous surfactant systems. The described process serves mainly two objectives; (a) waste utilization for preparation of commercially important nano-sulfur product and (b) reduction in environmental pollution. 1. G. Nagal, Chem. Eng. 104, 125 (1997).

Structural, Optical and Magnetic Properties of Ni Doped ZnS Nanoparticles

2018 ◽  
Vol 24 (8) ◽  
pp. 5640-5644
Author(s):  
B Sreenivasulu ◽  
S. Venkatramana Reddy ◽  
P. Venkateswara Reddy
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Absorption Spectra ◽  
Spherical Surface ◽  
Room Temperature Ferromagnetism ◽  
Average Particle Size ◽  
Precipitation Method ◽  
Chemical Compositions ◽  
Average Particle ◽  
X Ray

Pure ZnS and 3 mol% of Ni doped ZnS nano powders are prepared by chemical co-precipitation method. Properties of ZnS: Ni2+ nanoparticles are studied by X-ray diffraction Spectra (XRD), Raman spectroscopy (RS), Photoluminescence (PL), Absorption Spectra, Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDAX), Transmission electron microscopy (TEM) and Vibrating sample magnetometer (VSM). From XRD data, it conform the structure of ZnS, and particle size of pure and Ni doped ZnS data indicates the incorporation of Ni2+ in ZnS nanocrystal lattice. Raman spectra for pure and Ni doped samples exhibited vibrational modes confirm the structure of ZnS. Photoluminescence spectra reveal that the emission peaks are in UV and visible regions; this is confirming the absorption spectra. SEM micrographs show spherical morphology, and chemical compositions of samples are in stoichiometric proportions. TEM micro graphs show the spherical surface morphology and average particle size for pure and Ni2+ doped nanoparticles are in the range of 2–3 nm, this is good agreement with XRD results. M–H curves from VSM show room temperature ferromagnetism.

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