scholarly journals One-step synthesis of gold and silver non-spherical nanoparticles mediated by Eosin Methylene Blue agar

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Diego Alberto Lomelí-Rosales ◽  
Adalberto Zamudio-Ojeda ◽  
Sara Angélica Cortes-Llamas ◽  
Gilberto Velázquez-Juárez

AbstractNowadays, there are several approaches reported to accomplish the green synthesis of metal nanoparticles by using bacterial and fungi supernatants or by-products generated by these microorganisms. Therefore, agars as solely reductive regents have started to be used in order to obtain metal nanoparticles. This paper shows the results of the synthesis of gold and silver nanoparticles with different morphology, mainly triangular and truncated triangular, using Eosin Methylene Blue (EMB) agar as reducing agent. To control the reaction process, the necessary activation energy for the reducer was provided by three different techniques: microwave radiation, using a domestic microwave oven, ultraviolet radiation, and heating on a conventional plate. The evolution of the reduction process and stability of the samples was performed by ultraviolet visible spectroscopy. Morphology was carefully analyzed using high-resolution transmission electron microscopy (HRTEM) and Transmission electron microscopy (TEM). A one step synthesis for gold and silver nanoparticles was optimized with an eco-friendly and economic process.

Author(s):  
Nabraj Bhattarai ◽  
Subarna Khanal ◽  
Pushpa Raj Pudasaini ◽  
Shanna Pahl ◽  
Dulce Romero-Urbina

Citrate stabilized silver (Ag) colloidal solution were synthesized and characterized for crystallographic and surface properties by using transmission electron microscopy (TEM) and zeta potential measurement techniques. TEM investigation depicted the size of Ago ranges from 5 to 50 nm with smaller particles having single crystal structure while larger particles with structural defects (such as multiply twinned, high coalescence and Moire patterns). ?-potential measurement confirms the presence of Ag+ in nAg stock solution. The shift in ?-potential measurement by +25.1 mV in the filtered solution suggests the presence of Ag+ in Ago nanoparticles.


2019 ◽  
Vol 19 (11) ◽  
pp. 7487-7492 ◽  
Author(s):  
Supriya ◽  
Jayanta Kumar Basu ◽  
Sonali Sengupta

Synthesis of silver nanoparticles embedded on calcium alginate film and the catalytic property of this film in the reduction of nitrobenzene with sodium borohydride are demonstrated in this work. Natural polymer alginate acts as effective reducing and stabilizing agent in synthesis of silver nanoparticles. Effect of different parameters on the preparation of silver nanoparticles, such as, temperature, concentration of silver precursor and heating time was investigated. As-prepared silver nanoparticles were characterized by transmission electron microscopy, scanning electron microscopy, UV-Vis spectrometry, and atomic absorption spectrometry. Transmission electron microscopy analysis con-firms the formation of silver nanoparticles with particles size range of 3–19 nm and average particle size was found to be 10±4 nm. Effect of concentration of nitrobenzene and sodium borohydride, catalyst loading and temperature on the catalytic reduction of nitrobenzene was studied. Reusability of catalyst was examined in this reduction reaction and the catalyst shows good activity up to 10th run.


2013 ◽  
Vol 872 ◽  
pp. 74-78 ◽  
Author(s):  
S.P. Zhuravkov ◽  
Evgeny Plotnikov ◽  
Dmitry Martemiyanov ◽  
Nikolay A. Yavorovsky ◽  
Ulrich Hasse ◽  
...  

The morphological and structural characteristics of nanoscale silver particles obtained by the method of electric spark dispersion of metal granules in the liquid aprotic medium were obtained using atomic force microscopy, transmission electron microscopy, and dynamic light scattering spectroscopy. The specific surface, morphology, structure and the distribution by size of the particles are presented.


2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Akinobu Yamaguchi ◽  
Ikuo Okada ◽  
Takao Fukuoka ◽  
Mari Ishihara ◽  
Ikuya Sakurai ◽  
...  

The deposition of copper (Cu) and cupric oxide (Cu4O3, Cu2O, and CuO) particles in an aqueous copper sulfate (CuSO4) solution with additive alcohol such as methanol, ethanol, 2-propanol, and ethylene glycol has been studied by X-ray exposure from synchrotron radiation. An attenuated X-ray radiation time of 5 min allows for the synthesis of Cu, Cu4O3, Cu2O, and CuO nano/microscale particles and their aggregation into clusters. The morphology and composition of the synthesized Cu/cupric oxide particle clusters were characterized by scanning electron microscopy, scanning transmission electron microscopy, and high-resolution transmission electron microscopy with energy dispersive X-ray spectroscopy. Micro-Raman spectroscopy revealed that the clusters comprised cupric oxide core particles covered with Cu particles. Neither Cu/cupric oxide particles nor their clusters were formed without any alcohol additives. The effect of alcohol additives is attributed to the following sequential steps: photochemical reaction due to X-ray irradiation induces nucleation of the particles accompanying redox reaction and forms a cluster or aggregates by LaMer process and DLVO interactions. The procedure offers a novel route to synthesize the Cu/cupric oxide particles and aggregates. It also provides a novel additive manufacturing process or lithography of composite materials such as metal, oxide, and resin.


Micron ◽  
2015 ◽  
Vol 68 ◽  
pp. 23-26 ◽  
Author(s):  
D.A. Kirilenko ◽  
A.T. Dideykin ◽  
A.E. Aleksenskiy ◽  
A.A. Sitnikova ◽  
S.G. Konnikov ◽  
...  

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Wenqing Qin ◽  
Congren Yang ◽  
Ran Yi ◽  
Guanhua Gao

Single-crystalline - nanocubes were successfully obtained in large quantities through a facile one-step hydrothermal synthetic route under mild conditions. In this synthetic system, aqueous iron (III) nitrate () served as iron source and triethylamine served as precipitant and alkaline agent. By prolonging reaction time from 1 h to 24 h, the evolution process of -, from nanorhombohedra to nanohexahedron, and finally nanocube, was observed. The products were characterized by Powder X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), High-resolution Transmission Electron Microscopy (HRTEM), Selected-Area Electron Diffraction (SAED), and Fourier Transform Infrared Spectrometry (FTIR). The possible formation mechanism was discussed on basis of the experimental results.


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