Local controllability of hot electron and thermal effects enabled by chiral plasmonic nanostructures

Abstract

The control of hot electron (HE) and thermal effects induced by plasmonic nanostructures has recently attracted considerable attention. When illuminated by light with different circular polarization states, the circular dichroism signal of molecules adsorbed by plasmonic chiral nanostructures can control HE and thermal effects. These effects have the potential to enhance reaction rates and to change selectivity patterns in photothermal catalysis. Here, we propose an aluminum L-shaped chiral nanostructure system in which HE and thermal effects can be controlled in different regions of the nanostructure by changing the chirality of the excitation light. A large difference of 12.75% in the HE effect but a virtually identical thermal effect can be achieved in different regions of the nanostructure by selecting the appropriate probed region, while a large thermal effect difference of 65.67% but a virtually identical HE effect can be achieved in one region of the nanostructure by changing the polarization state of the excitation light. In addition, the HE and thermal chiral selectivity effects of double L-shaped nanostructures are investigated as these structures can be more easily controlled during asymmetric chiral growth and crystallization. This work combined with plasmonic chirality is beneficial for quantifying HE and thermal effects in photochemical reactions and provides theoretical support for designing catalysts and optimizing plasmonic platforms. Additionally, the local controllability of HE and thermal effects plays an essential role in high-resolution photochemical reactions, especially in single-molecule photochemical reactions.

Keywords

• chiral photochemistry
• circular dichroism
• hot electrons
• photothermal effect
• plasmonic resonance