Accelerated site-selective photooxidation on Au nanoparticles via electrochemically-assisted plasmonic hole ejection†
In order to induce electrochemical reactions by localized surface plasmon resonance (LSPR), semiconductors have been employed as electron or hole acceptors for plasmon-induced charge separation (PICS) in most cases. Here we replaced a semiconductor with a potential-controlled transparent electrode, and achieved accelerated photooxidation reactions at selected local sites on plasmonic metal nanoparticles. We demonstrate site-selective PbO2 deposition at the tips and sides of Au nanorods and PbO2 deposition and Au dissolution at the top and bottom of Au nanocubes, through the selective excitation of different LSPR modes. Energetic electron–hole pairs are generated at a plasmonic resonance site, and oxidation reactions are driven by hole ejection at the site. The complementary electrons are removed via the positively biased electrode, and consumed at a counter electrode by reduction reactions. In the case of the PbO2 deposition, formation of PbO2 nuclei is triggered by the hole ejection, and PbO2 is grown further in an electrochemical manner at an improved rate.
- This article is part of the themed collection: Nanoscale 10th Anniversary Special Issue