Synthesis of nano Ag powder by template and spray pyrolysis technology (original) (raw)

Solid silver particle production by spray pyrolysis

Journal of Aerosol Science, 1993

Solid, spherical, micron-sized silver metal particles were produced by spray pyrolysis from a silver nitrate solution. The effects of reaction temperature, carder gas type, solution concentration, and aerosol droplet size on the characteristics of the resultant silver particles were examined. Pure, dense, unagglomerated particles were produced with an ultrasonic generator at and above 600 ° C using Nz carder gas, and at and above 900°C using air as the carrier gas. Solid particle formation at temperatures below the melting point of silver (962°C) was attributed to sufficiently long residence times (3.5-54 s) which allowed aerosol-phase densification of the porous silver particles resulting from reaction of the precursor.

Effects of precursors of glass material on the characteristics of silver-glass composite powders prepared by spray pyrolysis

Metals and Materials International, 2011

The characteristics of silver-glass composite powders directly prepared by spray pyrolysis from spray solutions with different precursor types of Pb, Si and Ti components were investigated. The composite powders had spherical shape and submicron size irrespective of precursor types of glass material and glass content of the powders. The silver conducting films formed from the composite powders had dense structures irrespective of precursor types of glass material and glass content of the powders. The silver conducting film formed from the composite powders obtained from the spray solution with fumed titania as the source material of the Ti component had the lowest sheet resistance of 2.8 mΩ/sq. The sheet resistances of the silver conducting films changed from 2.8 mΩ/sq to 3.7 mΩ/sq according to the glass content of the composite powders at a firing temperature of 700 °C.

The particle size distribution (PSD) as criteria for comparison of silver powders obtained by different methods of synthesis and by conditions of electrolysis

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...

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.

Facile route to preparation of plate‐like silver powders

Micro & Nano Letters, 2014

Silver nanoplates with thickness of tens of nanometres and widths in the range of 5-10 μm were successfully prepared employing a facile solution-based route based on the redox reaction between silver ions and ferrous ions. Furthermore, the influences of the mass ratio of reactants, surfactant concentration, reaction temperature and the type of surfactants on the morphologies of silver powders were carefully studied. The phase structure and morphology of silver powders are characterised by X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy. The mass ratio of reactants, concentration of surfactant, reaction temperature and the type of surfactants were crucial factors in determining the morphologies of the final products. The formation mechanism of silver nanoplates is preliminarily discussed.

A new and effective chemical reduction method for preparation of nanosized silver powder and colloid dispersion

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.

Nanoparticles of silver powder obtained by mechano-chemical process

Journal of Experimental Nanoscience, 2008

The silver (Ag) powder was synthesised in a mechano-chemical (MC) process by inducing a solid-state displacement reaction between silver chloride (AgCl) and copper (Cu). The AgCl and Cu were ground in atmosphere conditions using a planetary ball mill. The reaction caused the mixture of AgCl and Cu to change the composition of the mixture, such as Ag and copper chloride (CuCl). CuCl was separated from MC product by leaching with ammonium hydroxide and we obtained Ag powder as the final product. Moreover, ascorbic acid (C 6 H 8 O 6) was used as the additive to improve dispersion of Ag powder during MC process. The ground powders, formed in the presence of additive, were characterised by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD determined that the reaction between AgCl and Cu was complete in almost all the experiments carried out. SEM examinations revealed that the size of the particles in the synthesised metallic Ag powder was in the range of 30-300 nm.

Studies on Properties of AG\AL2O3 Nanocomposite Synthesized by Solution Combustion Technique Under Novel Condition

Journal of Nanostructures, 2012

Ag\Al2O3 nanocomposite were synthesized by solution combustion Technique using ammonium carbonate as a new fuel under simultaneous combustion of alumina and silver particles condition. Samples prepared with different amount of silver, were characterized by XRD, BET, SEM and optical Absorption measurements. XRD analysis was used to determine the change in phase and size of the synthesized nanoparticle with adding silver. BET analysis showed that added silver reduced specific surface but which is still suitable for catalytic application. BJH analysis showed that pores in Ag/Al2O3 nano composite are mesoporous and in Al2O3 nano particles is microporous. TEM and SEM showed that silver was distributed completely homogenously in pores of Alumina, and didn’t change in surface of Alumina. Optical transmission showed the different existence of different Ag species.

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.

Comparative Morphological and Crystallographic Analysis of Electrochemically- and Chemically-Produced Silver Powder Particles

Metals

Silver powders chemically synthesized by reduction with hydrazine and those produced by electrolysis from the basic (nitrate) and complex (ammonium) electrolytes were examined by X-ray diffraction (XRD) and scanning electron microscopic (SEM) analysis of the produced particles. Morphologies of the obtained particles were very different at the macro level. The needle-like dendrites, as well as the mixture of irregular and regular crystals, were formed from the nitrate electrolyte, while the highly-branched pine-like dendrites with clearly noticeable spherical grains were formed from the ammonium electrolyte. The agglomerates of spherical grains were formed by reduction with hydrazine. In the particles obtained from the nitrate electrolyte, Ag crystallites were strongly oriented in the (111) plane. Although morphologies of Ag particles were very different at the macro level, the similarity at the micro level was observed between chemically-synthesized particles and those obtained by electrolysis from the ammonium electrolyte. Both types of particles were constructed from the spherical grains. This similarity at the micro level was accompanied by the similar XRD patterns, which were very close to the Ag standard with a random orientation of Ag crystallites. For the first time, morphologies of powder particles were correlated with their crystal structure.