Green Synthesis of Silver Nanoparticles and the Study of Optical Properties (original) (raw)
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Biological Sciences SYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES
2014
Silver nanoparticles exhibit new optical properties, which are observed neither in molecules nor in bulk metals. In the present study silver nanoparticle colloid was produced by chemical reduction method of silver salt (silver nitrate AgNO3) solution. The silver nanoparticles were characterized by using UV-VIS spectrometer and Scanning Electron Microscope (SEM). The Surface Plasmon Resonance peak in absorption spectra of silver colloidal solution showed an absorption maximum at 450 nm which indicated formation of silver nanoparticles. The size range 44nm to 56.55nm of silver nanoparticles was determined by using Scanning Electron Microscope (SEM). The absorbance range of prepared silver nanoparticles solution was checked on 1 st day, 5 th day, 18 th day and on 30 th day. There was no obvious change observed in peak position for 30 days, depicting the stability of Silver nanoparticles.
Green Synthesis of Silver Nanoparticles and Their Spectral Properties
Ukrainian Chemistry Journal
Spherical silver nanoparticles were synthesized by the chemical condensation method using aloe vera or chamomile extracts as a reducing agent. Depending on the type of extracts and its concentration, the size of AgNpcs varied from 7 to 50 nm by simply adjusting the ratio of the starting reagents. These extracts show reducing properties due to the presence of carbonyl compounds in their composition, in particular organic acids. It is shown that regulation of concentrations and synthesis conditions allows control of particle size. A change in the synthesis conditions affects the position of the surface plasmon resonance band, and therefore the optical properties of the studied systems. It has been proven that the synthesized silver nanoparticles do not require additional stabilization. Agglomeration processes occur only with a significant increase in concentration and heating time.
Synthesis and characterization of silver nanoparticles
2007
Silver nanoparticles have received considerable attention due to their attractive physical and chemical properties. The surface plasmon resonance and large effective scattering cross section of individual silver nanoparticles make them ideal candidates for molecular labeling, where phenomena such as surface enhance Raman scattering (SERS) can be exploited. In addition, silver nanoparticles have recently been shown to be a promising antimicrobial material. In the present research silver colloid was produced by sodium citrate reduction. The colloidal silver was incorporated by dip-coating to the polymer substrate. X-Ray Fluorescence Spectroscopy (XRF), Atomic force microscopy (AFM), ultraviolet-visible spectroscopy (UV-VIS ) and SERS indicate that the produced structures include metallic crystalline silver nanoparticles. The surface plasmon resonance peak in absorption spectra of silver particles showed an absorption maximum at 420-500 nm. The silver - polymer nanocomposites structures with selective light properties as a result of plasmon resonance shifting in the UV-VIS wavelength region were produced.
Synthesis of silver nanoparticles and their optical properties
Journal of Experimental Nanoscience, 2010
Silver nanoparticles have been synthesised by chemical reduction of silver nitrate solution by ethanol. The samples have been characterised by X-ray diffraction study. Transmission electron microscopy reveals the nanostructure of the particles produced. This study infers that the particles are mostly spherical in shape and the sizes are within 18 nm. The surface plasmon resonance peak in the UV-Vis absorption spectra shows maximum absorption at 422 nm. Fluorescence spectra of silver nanoparticles, which show an emission peak at 470 nm have also been studied.
The effect of temperature on green synthesis of silver nanoparticles
International Conference of Chemistry and Petrochemical Techniques (ICCPT)
This study, performed the green synthesis of silver nanoparticles at different temperatures using a cost-effective and environmentally friendly technique using Ruta leaf extract as a reducing agent for silver. AgNPs were characterized by UV-Vis spectroscopy, infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), EDX, and dynamic light scattering (DLS). The silver nanoparticles synthesized biologically were confirmed by changing their color from colorless to yellow and finally to brown. UV-visible spectroscopy showed that a blue shift of the surface plasmon absorption peak with increasing temperature. X-ray diffraction results showed the crystalline nature of AgNPs with a face-centered cubic structure (FCC). The stability and distribution size were revealed using DLS analysis. FESEM showed the formation of spherical nanoparticles less than 100 nm in size. The EDX technique showed that the presence of the silver component, which comes from AgNPs. The efficacy of silver nanoparticles prepared against bacteria of Staphylococcus aureus was tested, it was observed that the silver concentration has an influential role in inhibiting the bacteria.
Silver nanoparticles: New synthesis, characterization and photophysical properties
Materials Chemistry and Physics, 2007
In this paper, we report a new solution phase synthetic route to prepare silver(0) nanoparticles and their optical properties. The Ag(0) nanoparticles were prepared by reduction of AgNO 3 using t-BuONa-activated NaH in tetrahydrofuran at low temperature. The resulting t-BuONa-stabilized silver nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and UV-vis spectroscopy. The cubic face centered Ag(0) particles produced present a tight size distribution with an average radius of 3.3 ± 0.7 nm. The silver nanoparticles dispersed in tetrahydrofuran exhibit a broad and structured fluorescence band when exposed to oxygen. This result is corrolated with a red shift of the surface plasmon absorption band. This process has been attributed to production of charged nanoclusters, Ag m 2+ , produced by consecutive oxidation then chemisorption of Ag + onto metal surface.
Fabrication and characterization of gelatin stabilized silver nanoparticles under UV-Light
2011
Silver nanoparticles (Ag-NPs) were successfully synthesized using the UV irradiation of aqueous solutions containing AgNO 3 and gelatin as a silver source and stabilizer, respectively. The UV irradiation times influence the particles' diameter of the Ag-NPs, as evidenced from surface plasmon resonance (SPR) bands and transmission electron microscopy (TEM) images. When the UV irradiation time was increased, the mean size of particles continuously decreased as a result of photoinduced Ag-NPs fragmentation. Based on X-ray diffraction (XRD), the UV-irradiated Ag-NPs were a face-centered cubic (fcc) single crystal without any impurity. This study reveals that the UV irradiation-mediated method is a green chemistry and promising route for the synthesis of stable Ag-NPs for several applications (e.g., medical and surgical devices). The important advantages of this method are that it is cheap, easy, and free of toxic materials.
Biosynthesis of Green Silver Nanoparticles and Its UV-Vis Characterization
2020
In a recent time, silver nanoparticles (AgNPs) have attracted a lot of attention from researchers because of their special properties. In this paper green silver nanoparticles (AgNP) were synthetized from 2, 4 and 8 % w/v orange peel extracts. The synthesis was done by the process of chemical reduction in the presence of 1 mM silver nitrate (AgNO3) solution at 23 °C at 400 rpm for 6 hours. Orange peel extracts were used as capping agent to reduce 1mM solution to silver nanoparticles. The biosynthesized AgNPs were characterized by UVVis spectroscopy in the wavelength range from 300 to 600 nm with maximum of absorption at 460 nm. The results have shown that by increasing the concentration of peel extract increase the formation of silver nanoparticles. The advantage of this green method of synthesis is the use of fruit waste to create new valuable materials with potential antibacterial activity.
Spectral Study of Silver Nanoparticles Prepared by Chemical Method
Silver nanoparticles were prepared by the reduction of silver salt (silver nitrate AgNO3) solution using three different methods. The main differences between these methods is by belong to the reducing agent. It is found that the prepared silver nanoparticle was pure and stable for long time. UV-VIS spectrometry indicated formation of spherical silver nano particles. The surface plasmon resonance peaks in absorption spectra for silver colloidal solution showed that the absorption maximum range was at 380- 420 nm. The structures are confirmed by X-ray diffraction (XRD) and the crystallite size was determined from X-ray line broadening using the Scherrer's equation and it was about 32 nm.AFM measurements show that silver nano particles have the average diameter of 69.39 nm and 81.91 nm.