Plasmonic properties of supported Au and Au-Pd nanoparticles: optical and structural in situ characterization during their growth
Par Yvonne Soldo-Olivier, Institut Néel, CNRS & Université Grenoble Alpes
Mardi 19 Mars, 14h00, Salle des séminaires (215), 2ème étage, Bâtiment A4N
Abstract :
Recent experiments have shown an important increase of the catalytic activity for chemically synthesized gold or gold alloyed nanoparticles (NP) under visible light exposition. Such phenomenon has been attributed to surface plasmon resonance modes localized on nanoparticles (LSPR, local surface plasmon resonance). Plasmon enhanced visible light photocatalysis, transforming visible light into chemical energy via photocatalytic reactions, is extremely relevant in the context of energy-efficient processes using solar light. In this context, a deep comprehension of LSPR-assisted processes, especially at the nano/atomic level, is a key step in view of a large scale development.
Our approach consists in characterizing in situ during the NP growth the morpho-structural and optical properties of model systems, namely Au and Au-Pd nanoclusters deposited by molecular beam epitaxy (MBE) onto TiO2(110).
I will discuss the results obtained from the experiments we performed at SOLEIL synchrotron (France) by means of Grazing Incidence Small Angle X-ray Scattering (GISAXS), providing size, shape and inter-particle distance, Grazing Incidence X-ray Diffraction (GIXRD) for crystallographic properties and UV-Visible Surface Differential Reflectivity Spectroscopy (SDRS) for optical response.