arXiv subjects

Zelio Fusco

Publications and source records attributed to Zelio Fusco.

3 recordsLinked to original sources

arXiv2026

Tuning Plasmonic Metasurfaces via Phase Change Material Substrates for Modulating Reactivity in Light-Driven Reactions

Phase change materials provide a powerful platform for dynamically modulating optical responses in nanophotonic systems. While plasmonic metasurfaces have been widely employed to enhance photocatalytic efficiency and promote particular light-driven reactions, active and dynamical control over reaction pathways within a single device remains challenging. Here, we report a phase-induced tunable metasurface that tailors photoexcited electron populations through mode hybridization, enabling selective control over the reactivity of light-driven chemical processes. By exploiting thermally induced refractive-index switching in a Sb2S3 cavity, the plasmonic resonance strength of Au nanodisks is actively tuned via cavity-plasmon hybridization. This reconfiguration modulates the product yield of methylene blue degradation by a factor of 2.4, suppressing to 0.45 in the crystalline phase and enhancing to 1.09 in the amorphous phase. Importantly, this reconfigurable platform enables dynamic control of the reaction yield using a single metasurface architecture under identical illumination conditions. Our approach establishes a dynamically programmable light-driven reaction platform capable of precisely manipulating reaction reactivity, offering new opportunities for selective photocatalysis in complex multibranch reaction systems.

physics.optics↗

arXiv2025

Polarization-Sensitive Au-TiO2 Nanopillars for Tailored Photocatalytic Activity

Plasmonic metasurfaces play a crucial role in resonance-driven photocatalytic reactions by effectively enhancing reactivity via localized surface plasmon resonances. Catalytic activity can be selectively modulated by tuning the strength of plasmonic resonances through two primary non-thermal mechanisms: near-field enhancement and hot carrier injection, which govern the population of energetic carrier excited or injected into unoccupied molecular orbitals. We developed a set of polarization-sensitive metasurfaces consisting of elliptical Au-TiO2 nanopillars, specifically designed to plasmonically modulate the reactivity of a model reaction: the photocatalytic degradation of methylene blue. Surface-enhanced Raman spectroscopy reveals a polarization-dependent reaction yield in real-time, modulating from 4.7 (transverse electric polarization) to 9.98 (transverse magnetic polarization) in 10 s period, as quantified by the integrated area of the 480 cm-1 Raman peak and correlated with enhanced absorption at 633 nm. The single metasurface configuration enables continuous tuning of photocatalytic reactivity via active control of plasmonic resonance strength, as evidenced by the positive correlation between measured absorption and product yield. This dynamic approach provides a route to selectively enhance or suppress resonance-driven reactions, which can be further leveraged to achieve selectivity in multibranch reactions, guiding product yields toward desired outcomes.

physics.optics↗

arXiv2024

Ab-initio investigation of hot electron transfer in CO$_2$ plasmonic photocatalysis in presence of hydroxyl adsorbate

Photoreduction of carbon dioxide (CO$_2$) on plasmonic structures is of great interest in photocatalysis to aid selectivity. While species commonly found in reaction environments and associated intermediates can steer the reaction down different pathways by altering the potential energy landscape of the system, they are often not addressed when designing efficient plasmonic catalysts. Here, we perform an atomistic study of the effect of the hydroxyl group (OH) on CO$_2$ activation and hot electron generation and transfer using first-principle calculations. We show that the presence of OH is essential in breaking the linear symmetry of CO$_2$, which leads to a charge redistribution and a decrease in the O=C=O angle to 134°, thereby activating CO$_2$. Analysis of the partial density of states (pDOS) demonstrates that the OH group mediates the orbital hybridization between Au and CO$_2$ resulting in more accessible states, thus facilitating charge transfer. By employing time-dependent density functional theory (TDDFT), we quantify the fraction of hot electrons directly generated into hybridized molecular states at resonance, demonstrating a broader energy distribution and a 11% increase in charge-transfer in the presence of OH groups. We further show that the spectral overlap between excitation energy and plasmon resonance plays a critical role in efficiently modulating electron transfer processes. These findings contribute to the mechanistic understanding of plasmon-mediated reactions and demonstrate the importance of co-adsorbed species in tailoring the electron transfer processes, opening new avenues for enhancing selectivity.

physics.comp-ph↗