Modified in situ and self-catalytic growth method for fabrication of Ag-coated nanocomposites with tailorable optical properties

Inorganic or organic solid supported metal nanostructures have been attracted intensive interests in recent years. In this study, a novel and versatile approach for the preparation of solid supported silver nanocomposites is presented for the first time. In this method, the modified aldehyde groups on solid supporters are employed to reduce Ag[(NH3)2]+ ions. The in situ reduced silver nucleus are directly coated on the surfaces of the supports and then used as both seeds and catalysts for the self-catalytic growth of Ag NPs. In this reaction, no additional reduction and protective agents are needed. Moreover, the size of the Ag NPs can be tuned by varying the concentration of the Ag[(NH3)2]+ ions and the reaction time, which leads to the interesting change of the localized surface plasmon resonance absorption of the NPs. Such a synthesis method may realize the separation of nucleation and growth stages for the formation of Ag NPs and is proved to be a versatile method for the preparation of solid supported Ag nanocomposites (PS–Ag, Fe3O4–Ag, and SiO2–Ag), which would benefit the preparations and further applications of functional materials in near future.