Chiral Generation of Hot Carriers for Polarization-Sensitive Plasmonic Photocatalysis.

ABSTRACT

Mastering the manipulation of chirality at the nanoscale has long been a priority for chemists, physicists, and materials scientists, given its importance in the biochemical processes of the natural world and in the development of novel technologies. In this vein, the formation of novel metamaterials and sensing platforms resulting from the synergic combination of chirality and plasmonics has opened new avenues in nano-optics. Recently, the implementation of chiral plasmonic nanostructures in photocatalysis has been proposed theoretically as a means to drive polarization-dependent photochemistry. In the present work, we demonstrate that the use of inorganic nanometric chiral templates for the controlled assembly of Au and TiO2 nanoparticles leads to the formation of plasmon-based photocatalysts with polarization-dependent reactivity. The formation of plasmonic assemblies with chiroptical activities induces the asymmetric formation of hot electrons and holes generated via electromagnetic excitation, opening the door to novel photocatalytic and optoelectronic features. More precisely, we demonstrate that the reaction yield can be improved when the helicity of the circularly polarized light used to activate the plasmonic component matches the handedness of the chiral substrate. Our approach may enable new applications in the fields of chirality and photocatalysis, particularly toward plasmon-induced chiral photochemistry.