scholarly journals Synthesis and Characterization of Gold Nanoparticles Using Trisodium Citrate as a Reductant

2020 ◽  
Vol 2 (1) ◽  
pp. 10-16
Author(s):  
Astriana Dewi ◽  
Suriati Eka Putri ◽  
Pince Salempa

This research is an experimental study that aims to determine the characteristics of gold nanoparticles (Au-NPs) synthesized using trisodium citrate as a reducing agent. 0.4 mM HAuCl4 solution was synthesized using Na3C6H5O7 to convert Au3+ to Au0 with several variations of the reducing agent concentration, 3.5%; 5%; 6.5% and 8%. Determination of reaction time was measured using a UV-Vis spectrophotometer with time variations of 1, 5, 15, 30 and 45 minutes. Characterization of the size and lattice of Au-NPs crystals using X-Ray Difraction (XRD) and morphological characterization using Scanning Electron Microscopy (SEM). The results of the characterization, Au-NPs were produced blackish brown in color, and yields were 66.13%, 89%, 59.63% and 50.30% respectively for trisodium citrate reductant concentrations of 3.5%; 5%; 6.5% and 8%, with an average Au-NPs size of 46.97; 19.06; 50.03 and 39.68 nm, Face Centered Cubic (FCC) Crystal lattice and have a homogeneous morphology.

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Tizazu Abza ◽  
Dereje Gelanu Dadi ◽  
Fekadu Gashaw Hone ◽  
Tesfaye Chebelew Meharu ◽  
Gebremeskel Tekle ◽  
...  

Cobalt sulfide thin films were synthesized from acidic chemical baths by varying the deposition time. The powder X-ray diffraction studies indicated that there are hexagonal CoS, face-centered cubic Co3S4, and cubic Co9S8 phases of cobalt sulfide. The crystallite size of the hexagonal CoS phase decreased from 52.8 nm to 22.5 nm and that of the cubic Co9S8 phase increased from 11 nm to 60 nm as the deposition time increased from 2 hrs to 3.5 hrs. The scanning electron microscopic images revealed crack and pinhole free thin films with uniform and smooth background and few large polygonal grains on the surface. The band gap of the cobalt sulfide thin films decreased from 1.75 eV to 1.3 eV as the deposition time increased from 2 hrs to 3.5 hrs. The photoluminescence (PL) spectra of the films confirmed the emission of ultraviolet, violet, and blue lights. The intense PL emission of violet light at 384 nm had red shifted with increasing deposition time that could be resulted from the increase in the average crystallite size. The FTIR spectra of the films indicated the presence of OH, C-O-H, C-O, double sulfide, and Co-S groups. As the deposition time increased, the electrical resistivity of the cobalt sulfide thin films decreased due to the increase in both the crystallite size and the films’ thickness.


RSC Advances ◽  
2020 ◽  
Vol 10 (51) ◽  
pp. 30858-30869
Author(s):  
Phuong Que Tran Do ◽  
Vu Thi Huong ◽  
Nguyen Tran Truc Phuong ◽  
Thi-Hiep Nguyen ◽  
Hanh Kieu Thi Ta ◽  
...  

The development of improved methods for the synthesis of monodisperse gold nanoparticles (Au NPs) is of high priority because they can be used as substrates for surface-enhanced Raman scattering (SERS) applications relating to biological lipids.


2019 ◽  
Vol 290 ◽  
pp. 87-92
Author(s):  
Adamu Ibrahim Usman ◽  
Azlan Abdul Aziz ◽  
Osama Abu Noqta

A simple method to synthesized nanoparticles was satisfied by reduction of tetrachloroauric acid in the presence of palm oil fronds extracts as capping and reduced agents. The as-synthesized gold nanoparticles structures have a triangular and hexagonal shape that are of tens of nanometre in size. It was realized that good control shape of nano-hexagonal gold nanoparticles were obtained from nano-triangular gold nanoparticles in the absence of any soft template. The production techniques of the gold nanoparticles were examined by using UV-vis spectroscopy, EFTEM and XRD patterns, which showed peaks at (111), (200), (220), (311) and (222), that described the preferential structure of the AuNPs as face-centered cubic crystal


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Kamonpan Wongyai ◽  
Phitchayapak Wintachai ◽  
Rasimate Maungchang ◽  
Parawee Rattanakit

A green, simple, and rapid synthesis of gold nanoparticles using plant extract, Cryptolepis buchanani Roem. and Schult, and their applications are first described in this paper. The formation of gold nanoparticles was visually observed by the appearance of a ruby red color, which was further indicated by an absorption peak at 530 nm in UV-Vis spectroscopy. Optimization of reaction parameters for the gold nanoparticles was also investigated. Various analytical techniques were employed as part of the process of characterizing the resulting gold nanoparticles. Fourier transform infrared (FTIR) analysis revealed that the phenol compounds present in the extract were responsible for gold(III) reduction and stabilization of gold nanoparticles. Transmission electron microscopy (TEM) analysis showed that the gold nanoparticles were spherical in shape with an average diameter of 11 nm. Powder X-ray diffraction (XRD) pattern indicated that the green synthesis approach produced highly crystalline, face-centered cubic gold nanoparticles. Energy-dispersive X-ray spectroscopy (EDS) measurements confirmed the presence of elemental gold in the prepared nanoparticles. The negative zeta potential value of gold nanoparticles was found to be -30.28 mV. The green synthesized gold nanoparticles expressed effective antibacterial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Acinetobacter baumannii and exhibited an excellent catalytic property in terms of its reduction ability of methylene blue.


2020 ◽  
Vol 25 (11) ◽  
pp. 2003-2017
Author(s):  
Leiva Sergio ◽  
Moraes Gilberto J. De

Damages produced by eriophyid mites to Olea europaea subsp. europaea cv. arauco have been known for many years. In a previous publication, the presence of Aceria oleae (Nalepa) and Oxycenus maxwelli, (Keifer) in Argentina was reported, but the species was not definitively identified. In the past five years, damage caused by this mite to leaves, flowers and fruits in many production areas was very high, leading to the need for further investigations about this mite, the most numerous mite species on this plant in Argentina. The present paper is divided in three parts: a) a morphological characterization of A. oleae based on specimens collected in Argentina, with the use of SEM; b) a study of its life cycle; and c) an illustration of its damage to leaves and fruits. The morphological study led to the confirmation of the identity of the species and to the determination of morphological aspects not previously mentioned in the literature. Life cycle and damage were observed to be similar to what has been previously mentioned in the literature for the same mite in other countries.


2010 ◽  
Vol 97-101 ◽  
pp. 19-22 ◽  
Author(s):  
Yu Shiang Wu ◽  
Wen Ku Chang ◽  
Min Jou

Zinc stannate Zn2SnO4 (ZTO) nanoparticles were synthesized via a hydrothermal process utilizing sodium carbonate (Na2CO3) as a weak basic mineralizer. The samples were hydrothermally treated at 150, 200, and 250oC for 48 h. The X-ray diffraction (XRD) patterns show that the highly-crystalline ZTO nanostructure could be formed in a well-dispersed manner for the 250°C sample at a particle size of less than 50 nm. As determined from transmission electron microscopy (TEM) results, ZTO nanoparticles are face-centered cubic single crystals agglomerated together. The Raman spectra results showed that the ZTO nanocrystals have a spinel structure. Furthermore, photocatalytic activity was tested with methylene blue (MB) by UV irradiation. The ZTO synthesized by the 2 M Na2CO3 mineralizer at 250oC demonstrated excellent photocatalytic activity. The ZTO treated three different ways had three distinct UV-Visible absorption curves, which directly influences their corresponding photocatalytic activity.


2015 ◽  
Vol 799-800 ◽  
pp. 120-124 ◽  
Author(s):  
Mary Donnabelle L. Balela ◽  
Lalaine M. Dulin ◽  
Erica A. Garcia ◽  
M. Janelle H. Tica

Cobalt-nickel (Co-Ni) nanowires were formed by electroless deposition in ethylene glycol under external magnetic field. The effects of initial Co (II) and Ni (II) concentration on the surface and morphology of the synthesized nanowires were investigated by x-ray diffraction (XRD) and scanning electron microscope (SEM) respectively. An increase in the Co (II) concentration resulted in increase in diameter of the nanowires. However, the length of nanowires was observed to decrease. Higher Co (II) concentration resulted in a mixture of hexagonal close-packed and face-centered cubic Co-Ni nanowires. X-ray diffraction revealed that crystal growth occurred when the nanowires are annealed at 653 K for 10h.


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