Repression of photomediated morphological changes of silver nanoplates

The unique physicochemical properties of silver nanoparticles (AgNPs) give them the potential to be useful in various applications such as sensors, catalysts, and sterilizers. Among the nano-consumer products registered in Woodrow Wilson Center (i.e., inventory of nanotechnology-based consumer products), AgNPs are the most applicable material in the commercial market. To apply AgNPs in nano-consumer products, the stability of colloidal AgNPs must be first assured. Among the destabilizing factors such as temperature, pH, salt concentration, and light, the effect of room light irradiation on morphological changes of AgNPs was investigated. Herein, we attempted to review the mechanism of photo-oxidation of AgNPs and citrate under light irradiation and suggest a repression method for the photomediated morphological changes of AgNPs via addition of hydroxyl ions. Silver nanoplate (AgP) and silver nanosphere (AgS) were used and their surfaces were stabilized with citrate. Based on the TEM images, UV–vis spectra, and zeta potential, we found that additional OH− successively acted as a buffer to repress the photomediated morphological change of AgNPs.