Plasmonic solar water splitting

Abstract

Enhancing renewable energy storage is crucial, and solar water splitting (SWS) is a promising method for converting solar energy into hydrogen as a chemical fuel. The process faces significant challenges, primarily in finding materials that can efficiently facilitate the necessary redox reactions while utilizing solar energy effectively. Semiconductor (SC) photoelectrodes made of different metal oxides have been extensively studied, but their practical use is limited by poor light absorption and charge carrier recombination. Recently, a novel approach employing metal nanostructures to enhance photocatalytic efficiency through localized surface plasmons was introduced. This chapter outlines the mechanics of plasmonic water splitting systems, highlighting the function of plasmonic metal nanoparticles (NPs) as antennas that enhance light harvesting and charge separation in SCs. The dynamics of propagating surface plasmons (PSPs) and localized surface plasmons (LSPs) are explored, elucidating how these phenomena contribute to enhanced energy absorption and conversion. Furthermore, various mechanisms of plasmonic water splitting, including direct hot-electron transfer, localized enhancement of electromagnetic field, plasmon resonant energy transfer, plasmon-heating effect, far-field light scattering, and dipole-dipole coupling reaction are discussed. Collectively, these advancements highlight the transformative potential of plasmonic nanocomposites in addressing the limitations of traditional SC materials for efficient solar energy utilization. © 2025 Elsevier Inc. All rights reserved.