Traveling Hot Spots in Plasmonic Photocatalysis: Manipulating Interparticle Spacing for Real-Time Control of Electron Injection

Herein, we introduce a novel approach to achieve real-time control over the hot-electron injection process in metal-semiconductor photocatalysts. Such functionality is attained through the design of a hybrid nanocomposite in which plasmonic Au nanorods and TiO2 nanoparticles are synergistically integrated with a thermoresponsive polymer. In this manner, modifying the temperature of the system allows 1) precise regulation of the interparticle distance between the catalyst and the plasmonic component and 2) the reversible formation of plasmonic hot spots on the semiconductor. Both features can be simultaneously exploited to modulate the injection of hot electrons, thus boosting/inhibiting at will the photocatalytic activity of these heterostructures. This innovative conception enables dynamically adjustable performance of semiconductors, hence opening the door to the development of a new generation of plasmon-operated photocatalytic devices.