Development of Photoelectrochemical Sensing and Near-infrared Light to Energy Conversion by Localized Surface Plasmon Resonance of Plasmonic Nanoparticles

Abstract

Noble metal nanoparticles (NPs) and metal oxide NPs with appreciable free carrier concentrations show vivid colors with strong light absorption and scattering due to localized surface plasmon resonance (LSPR), being tunable with the NP size, shape, and chemical composition. The photoexcitation of LSPR peaks causes plasmon-induced charge separation (PICS), when these NPs are in contact with an appropriate semiconductor such as titanium dioxide (TiO₂). Generally, PICS involves the electron transfer from LSPR-excited NPs to the semiconductor, in which the light energy captured by the NPs can be directly converted into the electrochemical energy. PICS has been widely utilized in various applications, such as photovoltaics, photocatalysis, photochromism, nanofabrication beyond the diffraction limit, chemical sensing and biosensing. Here, we introduce plasmonic energy conversion systems reported in our recent papers, that is, photoelectrochemical LSPR sensors based on PICS and near-infrared photovoltaics using plasmonic molybdenum oxide (MoO_x) NPs.