Alternating and semicontinuous chemical reduction method for high production of silver nanoparticles

Synthesis of silver nanoparticles (AgNPs) was carried out in aqueous solutions. Silver nitrate was used as precursor, carboxymethyl cellulose (CMC) as stabilising agent, and sodium borohydride as reducing agent. The reaction was semicontinuous by feeding both the precursor and reducing agent into the stabilising agent aqueous solution in an alternated fashion. Weight ratios of 1:1 AgNO 3 :CMC were used in the reduction reactions. AgNPs were characterised by UV–vis spectroscopy, transmission electronic microscopy (TEM), and X‐ray diffraction. The formation of AgNPs was confirmed by the presence of an absorption peak about 400 nm using UV–vis spectrophotometry. Spheroidal nanoparticles with an average diameter between 5 and 90 nm were observed by TEM. High productivity of AgNPs was obtained at lower reaction times and at low temperature compared with others previously reported in the literature.