From well-defined plasmonic nanoparticles to hybrid materials for photonic and catalytic applications

Our team develops research on hybrid materials devoted to optical applications, especially in the fields of optical protection, bioimaging, photocatalysis. In particular the expertise lies in the design of original molecular systems, coupled with inorganic materials like plasmonic nanostructures and the characterization of optical interactions and responses (absorption, emission, nonlinear responses…).
In this context and through various studies, we will see the benefits and the way to use gold nanoparticles, from their well-controlled synthesis, and also their functionalization and incorporation in hybrid materials, to their impact on the optical and catalytic properties.
Among numerous classes of nanoparticles like spheres, hollow spheres or nanorods, we have particularly investigated gold nano-bipyramids (AuBPs) for several years. Indeed, these AuBPs exhibit intense and well-defined plasmon resonance, easily tunable with the aspect ratio, and also strong localized electromagnetic field in the vicinity of the tips. Currently, our optimized synthesis
method leads to well-designed AuBPs in high yield and in high concentration, with a sharp plasmon band tunable from 650 nm up to 2000 nm. We have recently developed an easy and general gold surface modification by a functional thiolated silicon polymer.
In addition to be an alternative to the use of surfactants or long-chain polymers in order to provide efficient colloidal stabilization in a wide range of solvent, this surface modification allows us to prepare homogeneous hybrid materials like gold-doped sol-gel silica presenting clear plasmon band. Association with various photoactive compounds have been explored and positive impact such as enhancement have been shown for photocatalytic properties of SiO2/TiO2 films, or for non-linear optical absorption of dye-doped glasses. Finally, we will present in particular our current efforts to synthetize core-shell AuBP@SiO2 NPs combining with rose Bengal for catalysis based on singlet oxygen generation.