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Single-Particle Spectroelectrochemistry: Plasmon-Mediated Catalytic Activity Enhancement by Electrochemical Surface Engineering in Individual Gold Nanorods

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Understanding the enhancement of plasmon-mediated electrocatalytic activity in individual gold nanorods (AuNRs) remains limited. Herein, we report a single-particle spectroelectrochemical study on the electrochemical growth and catalytic role of Cu and Cu x S layers on AuNRs, formed via controlled deposition potentials. Underpotential deposition (UPD) of Cu on AuNRs induces a blueshift and intensity enhancement in the localized surface plasmon resonance (LSPR) spectrum, attributed to increased electron density from Cu. At more cathodic potentials, bulk Cu─primarily as lumpy Cu x O─is deposited, introducing a new Cu-related LSPR peak. In situ LSPR tracking reveals insights into the electrochemical kinetics of Cu 2+ species and its effect on AuNR optoelectronic properties. Subsequent sulfur deposition forms a rough Cu x S semiconductor layer, causing LSPR damping, which is reversible upon sulfur removal. The intrinsic plasmonic activity of AuNRs is enhanced by Cu deposition through elevated electron density, while the Cu x S layer further boosts catalytic performance via interfacial charge separation. Therefore, our single-particle spectroelectrochemical study provides new insights into the mechanisms of plasmon-mediated catalysis and catalytic enhancement enabled by electrochemically formed metallic layers on individual AuNRs for the detection of nitroaromatics in chemical industries. This study also presents a strategy for tuning the optoelectronic and catalytic properties of individual AuNRs through electrochemical surface engineering.

Source: JACS Au

DOI: 10.1021/jacsau.5c00755

Authors: Mukunthan Ramasamy, Ji Won Ha

Institution: University of Ulsan

Language: English

Topic: Gold and Silver Nanoparticles Synthesis and Applications

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,500

Funder: National Research Foundation of Korea