Synthesis and Characterization of SiO2@TiO2@AuNPs & SiO2@AuNPs@TiO2 Core-Shell Nanomaterials Deposited on Glass/FTOs Substrates for photoelectrocatalytic studies

Hydrogen has emerged as a viable alternative to fossil fuels. The photocatalytic generation of hydrogen from aqueous alcohol solutions such as methanol and ethanol appears to be a realistic technique for transforming renewable solar energy into chemical fuel. Heterogeneous photocatalysts mediated by plasmonic metals have shown improved characteristics and efficiency in solar-to-energy conversion yields . At the Institut de Chimie Physique d’Orsay (ICP), it is observed that SiO2@TiO2@AuNPs and SiO2@AuNPs@TiO2 core-shell nanomaterials boost hydrogen generation. However, the reason for the different high yields of these structures remains uncertain. Sum-frequency generation (SFG) spectroscopy is an optical method for obtaining vibrational fingerprints of molecules at surfaces. It has chemical sensitivity and is surface-specific due to its symmetry features; thus, SFG has become a valuable tool for monitoring the surface chemistry of nano-objects. Our research aims to look into the precise mechanisms involved in hydrogen generation on the surfaces of these two different nanostructures, and monitor the reactions using SFG. The core-shell nanostructures had already been synthesized and studied at ICP. Currently, we deposited and characterized optically (UV-Vis) and structurally (SEM) different kind of layers on glass and FTO as substrates by spin-coating and USP-coating to be compatible with SFG spectroscopy.