Microlandscaping on a graphene oxide film via localized decoration of Ag nanoparticles

Abstract

A direct and facile method for micro-landscaping of Ag nanoparticles on reduced graphene oxide (rGO) is presented. This method employs a focused laser beam to achieve local reduction of Ag⁺ ions to Ag NPs by laser irradiation on a GO film that is submerged in AgNO₃ solution. Using this method, the Ag nanoparticles can be directly anchored on a rGO film, creating a microlandscape of Ag nanoparticles on the rGO film. In addition, varying the intensity of the laser beam can control the shapes, sizes and distributions of Ag nanoparticles. The resulting hybrid materials exhibit surface enhanced Raman scattering of up to 16 times depending on the size and number density of silver nanoparticles. In addition, the hybrid Ag–rGO material shows superior photoresponse when compared to rGO.