Investigating the catalytic activity of plasmonic nanostructures by SERS

• Grant number: 15/25807-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2016
• End date: November 13, 2017
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Paola Corio
• Grantee: Natália de Jesus da Silva Costa
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 12/13119-3 - Vibrational spectroscopy in condensed phases, AP.TEM

Abstract

Surface-enhanced Raman scattering (SERS) is a technique mainly used for the detection of compounds such as organic pollutants, antibiotics, toxins, in very low concentrations; and for diagnostics and imaging in biomedical applications. Plasmonic nanoparticles (Au, Ag Cu, and their bimetallics) are well investigated in SERS because, under visible light irradiation, these nanoparticles present an increase of the electromagnetic field on their surface due to localized surface plasmon resonances that affects the Raman scattering of molecules near them. In this way, the Raman signals for these molecules can be intensified up to 1012 times under optimal conditions. Therefore, SERS is one of the most sensitive techniques to study surface science, and becomes a powerful tool to investigate catalytic reactions on metallic surfaces. However, the number of studies of catalytic processes by SERS is low compared to its others applications. We aim to explore SERS potential in catalysis by the investigation of catalytic activity of anisotropic plasmonic nanoparticles of AuPd in the selective hydrogenation of nitroarenes and in the photoreduction of CO2. The studies will be focused on the explanation of the influence of the morphology and the stabilizer in the selectivity and activity of the nanocatalyst. Nanorods, nanostars and nanotriangules are the chosen anisotropic morphologies, with well-defined synthetic approach. The stabilizer influence will be investigated by ligand exchange and by immobilization of the nanoparticles on commercial TiO2 and SiO2 supports functionalized with different functional groups.