Formation and Stabilization of Anisotropic Palladium and Platinum Nanoparticles in Aqueous Polymer Solution Using Microwave Irradiation

2008 ◽  
Vol 61 (11) ◽  
pp. 833 ◽  
Author(s):  
Angshuman Pal ◽  
Sunil Shah ◽  
Debjani Chakraborty ◽  
Surekha Devi
Keyword(s):  
Microwave Irradiation ◽  
Platinum Nanoparticles ◽  
Palladium Nanoparticles ◽  
Pt Nanoparticles ◽  
Visible Spectroscopy ◽  
Aqueous Polymer ◽  
Transmission Electron ◽  
Aqueous Polymer Solution ◽  
Uv Visible ◽  
Palladium Particles

Anisotropic palladium and platinum nanoparticles were synthesized by reduction of the corresponding metal ions with hydrazine using polyacrylamide as a stabilizing agent in aqueous medium under microwave irradiation. The formation of particles was confirmed by UV-visible spectroscopy. The size and shape of the particles were determined using transmission electron microscopy. Rapid microwave heating resulted in ‘star-shaped’ palladium nanoparticles, but platinum nanoparticles were observed to be spherical with a distinctly visible 3–4 nm coating of polyacrylamide on their surface, which was not observed for the palladium particles. The Pt nanoparticles were used as a catalyst in the redox reaction.

Formation mechanism of Pd/PVP nanoparticles: effect of ultrasonic irradiation time

2018 ◽  
pp. 14-22
Author(s):  
Abderrafik Nemamcha
Keyword(s):  
Formation Mechanism ◽  
Ultrasonic Irradiation ◽  
Palladium Nanoparticles ◽  
Irradiation Time ◽  
Particle Surface ◽  
Ultrasound Irradiation ◽  
Visible Spectroscopy ◽  
Transmission Electron ◽  
Uv Visible ◽  
Sonochemical Reduction

The effects of ultrasonic irradiation time on the palladium nanoparticles (Pdns) formation mechanism have been investigated using UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). Pdns colloids have been prepared by ultrasonic irradiation of Pd(NO3)2 solutions at different irradiation times (from 30 to 180 minutes). The obtained results show that the rate of sonochemical reduction of Pd(II) ions has been found to be dependent upon the irradiation time. The kinetic of Pdns formation can also be correlated with the rate of sonochemical reduction ofPd(II) ions, as well as with the role of PVP molecules. The results suggest a three-step mechanism to describe the Pdns formation as a function of ultrasound irradiation time. During the first step, the Pd(II) ions are rapidly reduced to Pd(0) atoms, and when the concentration of Pd(0) atoms is sufficient for nucleation, the formation of primary particles occurs which are stabilised by a maximal number of PVP molecules. During the second step, these particles grow progressively by adsorption of the Pd(0) atoms and the obtained particles are coordinated to all available PVP molecules. The third step corresponds to decrease of the bounded PVP to the particle surface and the growth of the large particles at the expense of the unstable small ones. Keywords: Palladium nanoparticles, ultrasound irradiation, formation mechanism, UV-visible spectroscopy, FT-IR spectroscopy, TEM.  

scholarly journals Optical and Photoacoustic Properties of Laser-Ablated Silver Nanoparticles in a Carbon Dots Solution

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5798
Author(s):  
Amir Reza Sadrolhosseini ◽  
Ganesan Krishnan ◽  
Suhaidi Shafie ◽  
Suraya Abdul Rashid ◽  
Sulaiman Wadi Harun
Keyword(s):  
Silver Nanoparticles ◽  
Carbon Dots ◽  
Thermal Effusivity ◽  
Nonlinear Susceptibility ◽  
Time Range ◽  
Raman Signal ◽  
Optical Parameters ◽  
Visible Spectroscopy ◽  
Transmission Electron ◽  
Uv Visible

This study used the carbon dots solution for the laser ablation technique to fabricate silver nanoparticles. The ablation time range was from 5 min to 20 min. Analytical methods, including Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy, transmission electron microscopy, and Raman spectroscopy were used to categorize the prepared samples. The UV-visible and z-scan techniques provided optical parameters such as linear and nonlinear refractive indices in the range of 1.56759 to 1.81288 and 7.3769 × 10−10 cm2 W−1 to 9.5269 × 10−10 cm2 W−1 and the nonlinear susceptibility was measured in the range of 5.46 × 10−8 to 6.97 × 10−8 esu. The thermal effusivity of prepared samples, which were measured using the photoacoustic technique, were in the range of 0.0941 W s1/2 cm−2 K−1 to 0.8491 W s1/2 cm−2 K−1. The interaction of the prepared sample with fluoride was investigated using a Raman spectrometer. Consequently, the intensity of the Raman signal decreased with the increasing concentration of fluoride, and the detection limit is about 0.1 ppm.

Biosynthesis of Gold Nanoparticles with Serratia marcescens Bacteria

2015 ◽  
Vol 1132 ◽  
pp. 19-35
Author(s):  
S.O. Dozie-Nwachukwu ◽  
J.D. Obayemi ◽  
Y. Danyo ◽  
G. Etuk-Udo ◽  
N. Anuku ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Serratia Marcescens ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Color Changes ◽  
Transmission Electron ◽  
Helium Ion ◽  
Ph Conditions ◽  
Uv Visible ◽  
Ion Microscopy

This paper presents the biosynthesis of gold nanoparticles from the bacteria, Serratia marcescens.The intra-and extra-cellular synthesis of gold nanoparticles is shown to occur over a range of pH and incubation times in cell-free exracts and biomass ofserratia marcescensthat were reacted with 2.5mM Tetrachloroauric acid (HAuCl4). The formation of gold nanoparticles was identified initially via color changes from yellow auro-chloride to shades of red or purple in gold nanoparticle solutions. UV-Visible spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray spectroscopy (EDS), Helium Ion Microscopy (HIM) and Dynamic Light Scattering (DLS) were also used to characterize gold nanoparticles produced within a range of pH conditions. The results show clearly that the production of gold nanoparticles from cell-free extracts require shorter times than the production of gold nanoparticles from the biomass.

Mythology Merges with Technology for Majestic Production of Silver Nanoparticles: Rudraksha Enabled

2012 ◽  
Vol 585 ◽  
pp. 144-148
Author(s):  
Poushpi Dwivedi ◽  
S.S. Narvi ◽  
R.P. Tewari
Keyword(s):  
Silver Nanoparticles ◽  
Vital Role ◽  
Environmentally Benign ◽  
Size Analysis ◽  
Visible Spectroscopy ◽  
Efficient Manner ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Cost Efficient

In this nanoregime attempts to bring forth nanoparticles and nanomaterials are myriads, with there interesting and demanding applications in almost every field. Today the field of nanoscience has bloomed with the confluence of nanotechnology with material science, biology, biotechnology and medicine and the need for nanotechnology will only increase as miniaturization becomes extremely important in various arrays of life. Since time immemorial silver nanoparticles have been extensively used for hygienic and healing purposes, and even until most recently, it has indispensible vital role especially in the biomedical arena. Thus in an attempt to generate silver nanoparticles employing green, environmentally benign route, we have designed to converge mythology with technology, with the mystical production of silver nanoparticles, enabled by the blueberry beads of the plant Elaeocarpus granitrus Roxb., the Rudraksha. This non-degradable bead does not disintegrate, but retains the potentiality, even after unlimited production of silver nanoparticles, assisting infinite times. The extremely cost-efficient nanoparticles thus developed in a superiorly efficient manner were characterized through different techniques; like UV/visible spectroscopy, PL spectroscopy, transmission electron microscopy, energy dispersive X-ray analysis and nanoparticle size analysis.

Study on integration of aluminum-doped zinc oxide (AZO) thin films with graphene oxide (GO)

2018 ◽  
Vol 32 (19) ◽  
pp. 1840044
Author(s):  
Aditya Dalal ◽  
Animesh Mandal ◽  
Shubhada Adhi ◽  
Kiran Adhi
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Aluminum Doped Zinc Oxide ◽  
Uv Visible

Aluminum (0.5 at.%)-doped ZnO (AZO) thin films were deposited by pulsed laser deposition technique (PLD) in oxygen ambient of 10[Formula: see text] Torr. The deposited thin films were characterized by x-ray diffraction (XRD), photoluminescence (PL), Raman spectroscopy and uv–visible spectroscopy (UV–vis). Next, graphene oxide (GO) was synthesized by Hummers method and was characterized by XRD, UV–vis spectroscopy, Raman spectroscopy and transmission electron microscopy (TEM). Thereafter, GO solution was drop-casted on AZO thin films. These films were then characterized by Raman Spectroscopy, UV–vis spectroscopy and PL. Attempt is being made to comprehend the modifications in properties brought about by integration.

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 The High Photocatalytic Activity of SnO2Nanoparticles Synthesized by Hydrothermal Method

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Pham Van Viet ◽  
Cao Minh Thi ◽  
Le Van Hieu
Keyword(s):  
Photocatalytic Activity ◽  
Hydrothermal Method ◽  
High Photocatalytic Activity ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Uv Illumination ◽  
Transmission Electron ◽  
Uv Visible ◽  
Tin Oxide Nanoparticles

Tin oxide nanoparticles (SnO2NPs) were prepared at low temperature by hydrothermal method. Synthesized SnO2NPs were confirmedviacharacterization techniques such as UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), and Transmission Electron Microscope (TEM). The synthesized nanoparticles were in the size of 3 nm and they have high photocatalytic activity. The result showed that SnO2NPs degraded 88.88% MB solution after 30 minutes of UV illumination and reached 90.0% for 120 minutes (2 hours) of UV illumination. Moreover, they degraded 79.26% MB solution after 90 minutes (1.5 hours) under assisted sunlight illumination.

Nanoscale Growth of CdS and PbS Semiconductor within Calix[4]Arene Langmuir-Blodgett LB Film for Ion Sensing Application

2014 ◽  
Vol 895 ◽  
pp. 520-525
Author(s):  
Faridah Lisa Supian ◽  
Tim H. Richardson ◽  
Alexei V. Nabok ◽  
Mary Deasy ◽  
M. Syahriman M. Azmi
Keyword(s):  
Cadmium Sulphide ◽  
Multilayer Films ◽  
Visible Spectroscopy ◽  
Lead Sulphide ◽  
Pbs Nanoparticles ◽  
Langmuir Blodgett ◽  
Ion Sensing ◽  
Transmission Electron ◽  
Uv Visible ◽  
First Time

The characteristics of cadmium sulphide (CdS) and lead sulphide (PbS) nanoparticles, grown inside Langmuir-Blodgett (LB) multilayer films of 5,11,17,23-tetra-tert-butyl-25,27-dicarboxymethoxy-26,28-dihydroxycalix [arene (I), have been studied using ellipsometry, UV-visible spectroscopy, and transmission electron microscopy (TEM). Multilayer films were formed by transferring a floating Langmuir monolayer of I onto substrates using LB deposition and water subphase containing Pb2+ or Cd2+ ions. The nanoparticles were fabricated by exposing cadmium-or lead-containing multilayer films of I (20-80 monolayers thick) to hydrogen sulphide (H2S) gas for 12 hours. By Gaussian fitting of the absorbance - energy spectra, the size of the clusters and their dispersion were found to be 1.43±0.18 nm and 1.21±0.05 nm for CdS and PbS respectively. This is the first time that such thick LB films of an amphiphilic compound possessing such high thermal stability (m.pt. ~270°C) have been used as the vehicle for the formation of CdS and PbS semiconductor particles.

Biosynthesis of silver nanoparticles using lavender leaf and their applications for catalytic, sensing, and antioxidant activities

2016 ◽  
Vol 5 (6) ◽  
Author(s):  
Brajesh Kumar ◽  
Kumari Smita ◽  
Luis Cumbal
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Antioxidant Activities ◽  
Present Report ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Red Color ◽  
Uv Visible

AbstractThe present report summarizes an eco-friendly approach for the biosynthesis of silver nanoparticles (AgNPs) using the leaf extract of lavender. Initially, the synthesis of AgNPs was visually observed by the appearance of a wine red color. The optical property, morphology, and structure of as-synthesized AgNPs were characterized by UV-visible spectroscopy, dynamic light scattering, transmission electron microscopy, and X-ray diffraction analyses. All characterization data revealed the formation of crystalline and spherical AgNPs (Ag/Ag

A Facile Method for the Synthesis of Silver Nanoparticles in the Presence of Sodium Phosphate

2011 ◽  
Vol 109 ◽  
pp. 174-177 ◽  
Author(s):  
Yu Li Shi ◽  
Qi Zhou ◽  
Li Yun Lv ◽  
Wang Hong
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Sodium Phosphate ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Stabilizing Agents ◽  
Transmission Electron ◽  
Silver Nps ◽  
Uv Visible

A facile method for the synthesis of silver nanoparticles (NPs) has been developed by using sodium phosphate (Na3PO4) as stabilizing agents and glucose the reducing agent, respectively. The obtained silver NPs have been characterized by X-ray diffraction (XRD), UV-visible spectroscopy (UV-vis) and transmission electron microscopy (TEM). It was found that in the presence of sodium phosphate, silver NPs with different morphologies and sizes were obtained. The formation mechanism of diverse silver NPs was studied preliminarily.

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