Production of sub-micro sized silver particles by chemical reduction method in an environmentally-friendly manner (original) (raw)
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Preparation of Silver Powder used for Solar Cell Paste by Reduction Process
Energy Procedia, 2013
The preparation of fine silver particles is getting great attention due to their applications in electrical fields such as the fabrication of conductive pastes used in solar cell metallization. This study deals with the preparation of silver powders by a chemical reduction method using silver nitrate as a starting material, and either sodium or ammonium hydroxides as reactants, and formaldehyde as a reducing agent. The effects of ratio change between the silver nitrate and the base concentrations, on the characteristics of the silver micro particles, were examined. The physicochemical properties of the powders were evaluated using XRD, SEM, and granulometry. It was shown that the particle size and shape of the powder depend on the molar ratio of silver nitrate to base and, on the base nature.
Influence of reducing agents and surfactants on size and shape of silver fine powder particles
Metallurgical and Materials Engineering, 2014
Silver fine powder with different shapes and sizes were prepared by chemical reduction and characterized by scanning electron microscope. In this paper was presented the method for the preparation of the fine Ag powder with particles size smaller than 2.5 µm with suitability for the mass-production scale. Reduction was performed from nitrate solution directly by vigorous stirring at room temperature by three different reduction agents, with and without presence of two dispersants. Scanning electron microscopy revealed the preferred size of the particles obtained in all experiments with aim of the protecting agent. Larger particles and wider size distribution were obtained without surfactants although with average size of about 1 µm and small quantity of larger clusters of primary particles that is out of the fine powder classification. High purity, 99.999%, of silver was obtained in every experiment.
Materials Research Bulletin, 2003
Nanosized uniform silver powders and colloidal dispersions of silver were prepared from AgNO 3 by a chemical reduction method involving the intermediate preparation of Ag 2 O colloidal dispersion in the presence of sodium dodecyle sulfate CH 3 (CH 2) 11 OSO 3 Na as a surfactant. Several reducing agents such as hydrazine hydrate (N 2 H 4 ÁH 2 O), formaldehyde (HCOH) and glucose (C 6 H 10 O 5) have been found to be preferable in this study from a practical point of view. The silver powder with the 60-120 nm particle size and colloidal dispersion with the particles size 10-20 nm and 0.5-2.0 wt.% concentration were successfully synthesized.
Synthesis of micro-sized silver particles suitable for thick film contacts on solar cells
Proceedings of the 8th International Conference on Renewable Electrical Power Sources, 2020
The main goal of the study was to determine parameters for the production of the micro-sized silver powder applicable to the pastes that are in use in solar cell production and maintenance. In all experiments, silver nitrate solution and ascorbic acid were used, as a silver source and reducing agent, respectively. Polyvinylpyrrolidone and gelatine were used as dispersants. The dispersant in this system acts as a protective agent in a way that prevents agglomeration and aggregation processes. The influence of used agents was different, and one of the aims in the research was to determine the pros and cons of them. The optimal parameters of the synthesis were the solution temperature of 45 °C, pH=7, and concentrations of silver and ascorbic acid of 45 g/l and 30 g/l, respectively. Although PVP has proved to be a suitable protecting agent for the goals of the study, the best results were obtained with the use of gelatine as a dispersant in the concentration ratio against the silver ion...
Journal of Colloid and Interface Science, 2005
Uniform, well-dispersed silver particles of various morphologies have been prepared by reducing highly acidic silver nitrate solutions with ascorbic acid in the presence of a sodium naphthalene sulfonate-formaldehyde copolymer as dispersing agent. By varying the temperature of the reaction, the free acid content, the addition rate of the reductant, and the aging time, both isometric and anisotropic silver particles could be obtained. It was found that the latter were formed by aggregation of nanosize subunits, which were identified by electron microscopy and X-ray diffractometry.
Journal of Mining and Metallurgy, Section B: Metallurgy
Silver powders produced by both electrochemical (galvanostatic (DC) and potentiostatic (POT) regimes of electrolysis) and chemical processes were examined by scanning electron microscope, and particle size distribution (PSD) of the obtained particles was done. In the DC regime, the current densities of ?14.4 mA cm-2 for the nitrate (NIT; powder denoted with DC(NIT)) and ?13.05 mA cm-2 for the ammonium (AM; DC(AM)) electrolytes were applied. In the POT regime, the used overpotentials were ?90 mV (NIT(90)) and ?150 mV (NIT(150)) for the nitrate, and ?625 mV (AM(625)) and ?925 mV (AM(925)) for the ammonium electrolytes. Reduction with hydrazine was used for chemical synthesis (powder denoted with HYD). On the basis of SEM and PSD analysis, Ag powders were grouped into three groups. In the first group DC(AM), AM(925) and HYD powders with the (8.4?8.9 %) volume ratios were placed. In the second group were AM(625) and DC(NIT) powders with the (6.5?6.6 %) volume ratios. NIT(90) and NIT(150...
The Preparation of Nano Silver by Chemical Reduction Method
Journal of Modern Physics, 2022
A silver nanostructures prepared by using chemical reduction method. The silver nanoparticles were prepared with diameters of about (20 nm). Numerous techniques had been used to study the optical, structural like the UV-Vis absorption spectrometer, Ttransmission Electron Microscopy (TEM), Field-Emission Scanning Electron microscope (FESEM), and X-ray diffraction (XRD). The practical results exhibited the absorption spectrum of the prepared nanoparticles at (357 nm), it was found that there is a relationship between the positions of the optical absorption peak and the size of the silver nanoparticles. The analysis of TEM results showed the presence of nanoparticles in the range (20 nm). The analyzing of XRD results explained the crystal structure for silver nanoparticles. It is found a cubic unit cell have a lattice constants (a = 4.0855 Å), with the Miller indices were (111), (002), (002), and (113).
Analysis of Silver Nanoparticles Produced by Chemical Reduction of Silver Salt Solution
In the present research silver colloid was produced by chemical reduction of silver salt (silver nitrate AgNO3) solution. As a reducer sodium citrate was used. UV-VIS spectrometry indicated formation of nanoparticles. The surface plasmon resonance peak in absorption spectra of silver colloidal solution showed an absorption maximum at 450 nm. Comparison of theoretical (Mie light scattering theory) and experimental results showed that diameter of silver nanoparticles in colloidal solution is about 100 nm. Silver nanoparticles were deposited on two substrates: silica (SiO2) and polyethylene terephthalate (PET) modified with various polymers (polycarbonate (PC), polymethyl methacrylate (PMMA), polystyrene (PS)). The colloidal silver was incorporated by dip-coating to the polymer-substrate structures. X-ray fluorescence spectroscopy (XRFS) and atomic force microscopy (AFM) results indicate that produced structures include silver nanoparticles. It was found that during deposition, silver ...
Advanced Powder Technology, 2012
Spherical and mono-disperse micro-silver powder, a kind of silver powder with controllable size and high tap density, was prepared by using silver nitrate as metal source, ascorbic acid as reducing agent and gum arabic as dispersant under traditional chemical reduction method. The result of SEM images shown the spherical and mono-disperse silver powder with average particle size of about 1-2 lm and narrow particle size distribution was obtained. By varying the concentration of the reactants, dosage of dispersant and the pH of the mixture solution of ascorbic acid and gum arabic, the silver particles showed different size, and different size distribution. It was also found that the morphology of silver particles could transform from sphere to polyhedron and the tap density of silver powder was increased with the prolonging of reactants mixing time.
SYNTHESIS AND CHARACTERIZATIONS OF SILVER NANO PARTICLES USING CHEMICAL REACTION METHOD
In the present investigation colloidal silver nanoparticles was prepared by chemical reaction method from silver nitrate (AgNO3) and sodium citrate (Na3C6H5O7) in water. The preparation method were achieved at three levels of temperature (100, 150 and 200℃) the produced silver nanoparticles characterize by UV-vis Visible Spectroscopy, Scanning Electron Microscopy (SEM) and Particle Size analyzer the result of particle size analyzer show that their size distribution to lie in the range of (58.9-202) nm. The results show that silver nanoparticles are 58.9, 76.4 and 202 nm at temperatures of (100, 150, 200) ℃, respectively can be produced.