Surface Plasmon Resonance-Triggered Local Electromagnetic\nField Advances Photocatalytic and Photoelectrochemical Performance\nof Plasmonic Metal/Semiconductor Composite

Abstract

Introducing\nplasmonic metallic nanoparticles into semiconductor\nphotocatalysts is a promising strategy to achieve high solar energy\nconversion. Plasmonic metallic nanoparticles can transfer energy to\nadjacent semiconductors in a variety of ways, but the contribution\nof each pathway to the photocatalytic process still needs to be made\nclear. In this work, we designed a composite of Au@SiO₂/SnO₂ to separately study the impact of local electromagnetic\nfield (LEMF) induced by surface plasmon resonance (SPR) of metal nanoparticles\non the photocatalytic and photoelectrochemical performance of semiconductors\nby excluding other charge/energy transfer pathways. The result from\nphotocatalytic degradation and photoelectrochemical measurement indicates\nthat LEMF around Au@SiO₂ can promote the formation of electron–hole\npairs in nearby SnO₂ without the overlap between the metallic\nSPR band and the semiconductor absorption spectrum. This promotion\neffect is closely related to the distance between SnO₂ and\nAu@SiO₂, which almost disappears when the gap between the\ntwo components is more significant than 10 nm. This study provides\na perspective method to explore the energy transfer between plasmonic\nnanoparticles and semiconductors.