Optical and structural characterization of core-shell nanomaterials(SiO2@TiO2@AuNPs and SiO2@AuNPs@TiO2) for H2 production

Hydrogen is one of the potential clean energy sources that could address two major worldwide concerns: energy crises and environmental difficulties. Hydrogen production often involves the use of fossil-based technologies, which emit a significant amount of greenhouse gases in the process. As a result, one of the primary objectives of the last several decades has been to decarbonize the industry. Finding affordable, environmentally friendly, and dependable hydrogen generation systems with minimal emissions is essential for achieving this goal [1]. At the Institut de Chimie Physique d'Orsay (ICP), we found a promising way to increase the yield of H2 production taking profit of a core-shell structure with two different configurations (SiO2@TiO2@AuNPs and SiO2@AuNPs@TiO2) [2]. However, the difference in H2 yield between these two structures remains unknown and requires in-depth investigation. Using optical techniques such as surface sensitivity SFG spectroscopy can help track and monitor the steps involved in H2 production at the surfaces of these structures. SFG spectroscopy is an in-situ optical probe that has succeeded in monitoring in-situ interfaces [3]. Therefore, we use the same approach on these core-shell nanomaterials to provide an exact pathway to the chemical reactions that occur during H2 production. The core-shell nanomaterials have been synthesized and studied, and the coating optimized for SFG spectroscopy. We have used different deposition techniques (USP coating and spin coating) and substrates. Additionally, we have characterized the samples using spectroscopy techniques and SEM imaging to better understand the chemical and structural properties of these materials. At the end, our findings could potentially pave the way to have a coupled fundamental view of in-situ surface chemistry and could impact the field of green energy production.