Enhancement in the nonlinear optical properties of silver nanoprisms through graphene oxide anchoring†

Efficient nonlinear optical materials remain a subject of significant interest in the scientific community, with ongoing efforts focused on optimizing their properties for practical applications. This paper aims at exploring how the nonlinear optical properties of silver nanoprisms are affected by the interaction with graphene oxide sheets. For this purpose, we produce nanocomposites consisting of citrate-passivated silver nanoprisms anchored both electrostatically and covalently on graphene oxide nanosheets in a cost-effective and reproducible manner. The novelty of the technique hinges on the covalent functionalization of silver nanoprisms onto graphene oxide (GO) nanosheets according to the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride crosslinking method, using the existing carboxylic groups present both at the surfaces of the nanoprisms and the GO nanosheets. The formed hybrid nanocomposites were characterized by TEM measurements and exhibit nonlinear optical (NLO) properties, in particular a strong second harmonic scattering response as well as a multiphoton excited fluorescence spectrum characterized by a broad band in the visible range between 350 and 700 nm. In addition, the NLO response is sensitive to the nature of the interaction (electrostatic or covalent), which might be attributed to different charge transfer capabilities between covalently or electrostatically bound silver particles onto graphene oxide. Such nanocomposites are therefore promising for new applications in the areas of optoelectronics and photovoltaics.