Plasmonic Catalysis, Photoredox Chemistry, and Photosynthesis

The plasmonic excitations of metal nanostructures have been shown to result in the generation of energetic charge carriers. In this chapter, we discuss how energetic carriers produced by plasmonic excitation of Au nanoparticles can be harvested and utilized for driving multi-electron redox reactions. While such plasmon-driven photoredox chemistry is fairly general, we discuss its application for important energy relevant transformations such as the splitting of H₂O and the conversion of CO₂ to hydrocarbon fuels. In these schemes, plasmonic excitation is not just a source of kinetic enhancement; plasmonic excitation can modify the reaction mechanism or pathway and product selectivity. It is also possible for the free energy of plasmonic excitations to be harvested in the form of energetic carriers, enabling thermodynamically uphill reactions that are otherwise unfavorable in the dark. We label such processes as plasmonic photosynthesis. The chapter ends with a discussion of the current challenges and opportunities in the field of plasmonic photoredox chemistry.