The laser wavelength-dependent surface catalyzed activity of single zinc oxide nanorods decorated with silver nanoparticles.

Selecting the optimal excitation wavelength is crucial for maximizing the efficiency of plasmon-driven chemical reactions. In this study, we demonstrate wavelength-dependent surface catalysis on a precisely engineered hybrid nanostructure, composed of a single zinc oxide nanorod decorated with silver nanoparticles. Theoretical simulations revealed a strong localized surface plasmon resonance, generating a maximum electromagnetic field of 1.65 × 10⁵. By monitoring a model catalytic reaction under excitation at 532 nm and 633 nm, we found that the reaction rate was significantly higher under 532 nm than under 633 nm light. The performance improvement stems from enhanced hot-carrier generation efficiency at 532 nm, which surpasses the efficiency at 633 nm by a factor of 5.52. This finding, elucidated at the single-particle level, provides direct evidence of wavelength-selective catalysis and offers a clear strategy for enhancing future plasmonic applications.