Review of Hot-Hole Photocatalysis in Plasmonic Nanostructures

High Resolution Image Download MS PowerPoint Slide The transformation of solar energy into chemical energy represents a sustainable approach to transitioning from fossil fuels to renewable energy. Photocatalysis using nanostructures offers a clean and efficient method for storing solar energy in chemical fuels that can be readily transported and used when needed. Among solar energy conversion methods, localized surface plasmon resonance (LSPR)-enhanced photocatalysis is particularly promising as it enables the harnessing of energy across the entire solar spectrum, including the near-infrared region. The key mechanism behind the enhanced photoactivity of plasmonic nanostructures is the LSPR-induced hot-carrier transfer. While significant advancements have been made in plasmonic photocatalysis driven by hot-electron transfer, systems based on hot-hole transfer remain underdeveloped despite their importance. This review highlights recent developments and discoveries related to LSPR-induced hot-hole transfer in plasmonic metal nanocrystals and plasmonic semiconductor nanostructures with a focus on their applications in photocatalysis. Additionally, emerging plasmonic nanomaterials are discussed, providing insight into the potential for utilizing LSPR-induced hot-holes in advanced photocatalytic systems. The physical principles governing LSPR in both metals and semiconductors are first introduced, followed by a discussion of the ultrafast charge dynamics of LSPR-induced hot-carriers. Representative plasmonic photocatalytic systems, including metal–semiconductor heterojunctions, molecule-functionalized plasmonic metals, and self-doped plasmonic semiconductors, are reviewed to illustrate the direct involvement of hot-holes in photocatalytic reactions. In addition, emerging plasmonic nanomaterials and strategies of maneuvering hot-hole dynamics are highlighted as a forward-looking perspective for leveraging the oxidative power of hot-holes in next-generation plasmonic systems for efficient and tunable solar-to-fuel energy conversion.