UV photo-mediated size-focusing synthesis of silver nanoclusters

Abstract

In this work, we first report the photo-mediated size-focusing synthesis of glutathione (SG)-protected atomically precise Ag nanoclusters (Ag NCs). This photo-mediated size-focusing synthesis comprises a two-step protocol: (i) the reduction of Ag ions by NaBH₄ to form polydisperse Ag NC intermediates and (ii) the subsequent photo-mediated size-focusing of these intermediates under 365 nm UV irradiation, producing monodisperse Ag₃₂(SG)₁₉ NCs. The role of light in the size-focusing synthesis of Ag NCs was investigated. We have demonstrated that 365 nm UV light irradiation under air/O₂ is an important parameter for the synthesis of well-defined Ag NCs via the photo-mediated size-focusing process due to the UV light/oxygen-sensitive properties of Ag.