Preparation and characterization of silver-iron bimetallic nanoparticles on activated carbon using plasma in liquid process

The mono and bi-metallic nanoparticles have conspicuous properties and are widely used in the environment, energy, and medical fields. In this study, bimetallic nanoparticles composed of silver and iron were precipitated on the surface of activated carbon in a single process using plasma in liquid process (PLP). Silver-iron ions and various radicals were actively generated in the aqueous reactant solution by the PLP. Although metals were precipitated on AC depending on the number of precursors added to the aqueous reactant solution, the standard reduction potential of silver ions was higher than that of iron ions, so silver precipitated on AC. The silver precipitate on AC was a mixture of metallic silver and silver oxide, and iron was present as Fe₃ O₄. Spherical nanoparticles, 100–120 nm in size, were observed on the surface of the Ag-Fe/AC composite. The composition of the bimetallic nanoparticles could be controlled by considering the ionization tendency and standard reduction potential of metal ions and controlling the concentration of the precursors. The PLP presented in this study can be applied to the preparing method of bimetallic nanoparticle/carbon materials and can be expected to be used in the prepare of energy and environmental materials such as MFC and absorption materials for removing pollutants.