Rational design for gold nanoparticle-based plasmonic catalysts and electrodes for water oxidation towards artificial photosynthesis.

The oxygen evolution reaction (OER) with a large overpotential is the key step common to artificial photosynthesis. In semiconductor photocatalysts, the light available to the reactions is usually limited to UV or visible with wavelengths shorter than the absorption edge of the semiconductors. On the other hand, gold nanoparticle (Au NP)-based plasmonic photocatalysts, particularly hot-electron transfer (HET)-type plasmonic photocatalysts, have the capability to utilize visible-to-near infrared light that makes up most sunlight as a driving force for the energetically uphill reactions. In recent years, experimental and theoretical studies on HET-type plasmonic photocatalysts consisting of Au NPs and a semiconductor have been intensively pursued. This perspective article highlights the fundamentals and recent progress of Au NP-based HET-type plasmonic photocatalysts for OER. After the introduction, the basics for the rational design of plasmonic photocatalysts are treated first. Secondly, the concrete design for the plasmonic photocatalysts is dealt with in the order of semiconductors, Au NPs, and their interface. Thirdly, recent advanced studies on plasmonic photocatalysts for OER are described. Finally, the conclusions are summarized with a direction for future research on plasmonic photocatalysts.