Synthesis of silver nanoparticles prepared in aqueous solutions using helium dc microplasma jet

Abstract Silver nanoparticles (AgNPs) were synthesized in aqueous solutions by reduction of silver nitrate (AgNO 3 ) assisted by a helium dc microplasma jet at atmospheric pressure without additional chemical reducing agents. Surfactant-free AgNPs were obtained at low initial AgNO 3 precursor concentrations ≤0.5 mM. A surface plasmon resonance peak at approximately 400 nm confirmed the presence of AgNPs. At higher concentrations, sucrose was used to prevent agglomeration and cap the growth of nanoparticles. The effects of the molar ratio of sucrose/AgNO 3 on the size distribution and morphologies of AgNPs were investigated. The average sizes of AgNPs synthesized at molar ratios of 20, 50, and 60% were 11.2 ± 0.4, 10.0 ± 0.2, and 6.2 ± 0.1 nm, respectively.