Plasmon-driven charge dynamics for efficient visible-light catalysis
Abstract
Localized surface plasmon resonance (LSPR) in metal nanoparticles (NPs) induces strong near-field enhancement under visible and near-infrared illumination, enabling advanced applications in molecular sensing, photoelectric conversion, and photothermal therapy. Upon light excitation, the rapid relaxation of free electrons in metallic NPs generates hot carriers. When coupled with semiconductors in engineered hybrid nanostructures, these hot carriers can undergo ultrafast interfacial transfer, significantly extending their lifetimes to the nanosecond regime. This process holds great promise for enhancing photocatalytic activity and photocurrent generation. However, the underlying mechanisms of charge separation and transfer at the plasmonic-semiconductor interface remain incompletely understood, limiting further optimization of energy conversion efficiency. To address this, time-resolved spectroscopic techniques have become essential. In our recent studies, femtosecond-resolved spectroscopy has revealed critical insights into the charge transfer dynamics at these hybrid interfaces.
Our presentation will cover recent findings on charge transfer in a (Au NP array)-(TiO2 film)-(Au film) stacked structure using femtosecond transient absorption spectroscopy, alongside insights from silver nanowire structures for visible light photocatalysis and electron diffusion simulations.
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25-28 June 2025, National Institute of Physics, University of the Philippines Diliman
Please visit the SPP2025 activity webpage for more information on this year's Physics Congress.