Synthesis of stearic acid-stabilized silver nanoparticles in aqueous solution

•Silver nanoparticles is prepared using stearic acid as capping agents in aqueous.•Stearic acid is first used for synthesis of silver nanoparticles in aqueous solution.•No organic solvent was used in the synthesis process.•The small, well-dispersed, spherical particles are from 3 to 15 nm.•This newly developed method can be extended to the synthesis of other metal colloid.

A practical and convenient method for the synthesis of highly stable and small sized silver nanoparticles with narrow distribution from 3 nm to 15 nm is reported. Silver nitrate, stearic acid and hydrazine hydrate, were used as silver precursor, capping agents and reducing agents respectively. The formation of silver nanoparticles was observed by the change of color from milky white to dark red. The silver nanoparticles were characterized by transmission electron microscopy (TEM), UV-visible spectroscopy (UV-vis) and X-ray diffraction (XRD). The results demonstrated that the obtained metallic nanoparticles were single crystalline silver nanoparticles. The effects of the reaction temperature, the amount of stearic acid and ammonia on the particle size were investigated. The obtained silver nanoparticles are stable and will possibly be used in electronic applications. The preparation method is simple and may be extended to other noble metal for other technological applications.

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