The Physics & Astronomy Colloquium Series presents Alberto Naldoni of University of Turin, Department of Chemistry, Torino, Italy, discussing "Photochemical Energy Conversion at the Nanoscale with Integrated Photonics" on Oct. 7.

Abstract: Plasmonic nanostructures can dramatically increase the chemical reaction rates by providing more efficient solar-to-chemical energy conversion. Upon light excitation, metallic nanostructures sustain the collective oscillation of surface electrons, i.e. surface plasmons, generating several non-linear effects such as intense electromagnetic fields and non-thermal (hot) carriers. Their thermalization results in intense local heating of the nanostructures and of their surroundings. All these effects can alter the reaction pathways and boost the reaction kinetics. Such discoveries have boosted the field of plasmonic photocatalysis, which aims at driving industrially-relevant chemical reactions using solar illumination.

In this colloquium talk, I will first show a newly developed technique enabling the investigation of the catalytic sites over plasmonic nanostructures on planar substrates with deeply subwavelength resolution.

In the second part of the talk, I will focus on how to fabricate large-area plasmonic metasurfaces exhibiting a rich set of electromagnetic resonances and their integration in photoelectrochemical water splitting cells, direct alcohol fuel cells, and photochemical devices for hydrogen evolution. I will discuss the complex relationship between the optical resonances of the plasmonic metasurfaces with their chemical reactivity by distinguishing the various effects enhancing their photochemical performance.