Structural and optical properties of novel surfactant-coatedYb@TiO2 nanoparticles

Abstract In this paper a novel hybrid approach tosynthesise composite nanoparticles is presented. It isbased on the laser ablation of a bulk target (Yb)immersed in a reversed micellar solution whichcontains nanoparticles of a different host material(TiO2 nanoparticles) previously synthesised by chemicalmethod. This approach thus exploits the advantagesof the chemical synthesis through reversed micellarsolution (size control, nanoparticle stabilisation), andof the laser ablation (‘‘clean’’ synthesis, no sidereactions). Central role is played by the microscopicprocesses controlling the deposition of the ablated Ybatoms onto the surface of TiO2 nanoparticles whichactually behave as nucleation seeds. The structuralfeatures of the resulting Yb@TiO2 composite nanoparticleshave been studied by Transmission ElectronMicroscopy, whereas their peculiar optical propertieshave been explored by UV–Vis spectroscopy andsteady-state fluorescence. Results consistently showthe formation of Yb and TiO2 glued nanodomains toform nearly spherical and non-interacting nanoparticleswith enhanced photophysical properties.