Structural transition of synthesized silver nanoparticles under irradiation

Abstract

We have developed a novel one-step method for photoreduction synthesis of morphology-controlled Ag nanoparticles (AgNPs) under the irradiation of narrow band blue light emitting diodes. The results showed that AgNPs with different morphologies can be prepared by controlling the irradiation time. More importantly, a new spectrophotometry based on the silver phenanthroline-eosin ion association system was established to detect the concentration of Ag+. In the presence of polyvinyl alcohol, Ag+ can combine with 2,4,5-7-tetrabromofluorescein disodium salt and 1,10-phenanthroline monohydrate forming red ternary complex in ammonium acetate buffer (pH 7.0). The new method was applied to determine the concentration of Ag+ during the formation of AgNPs. According to the changes of Ag+ concentration and morphologies, a potential mechanism for the structural transition of AgNPs was given.