FIP Seminar: Co-hosted with Chemistry, MEMS & MatSci 'Plasmonic Photosynthesis'
Mimicking plant photosynthesis requires a synthetic photocatalyst that absorbs sunlight and uses that energy efficiently to convert CO2 into energy-dense hydrocarbons. My talk will make the case that noble metal nanostructures, which exhibit collective free electron resonances called plasmons, may be well-suited to this task. Not only do plasmonic nanoparticles of Au, Ag, and Cu absorb visible light efficiently, this strong-light-matter interaction can be paired with their ability to activate CO2. We have had preliminary success with plasmonic Au catalysts, which drive kinetically challenging multi-electron multi-proton reduction of CO2 to hydrocarbons under visible-light excitation. The product selectivity is dependent on the nature of the exciting light, which hints that a novel phenomenon is at work. In order to understand the light-driven pathway for CO2 reduction, we have spectroscopically monitored the reaction on a single plasmonic nanoparticle. The mechanism by which plasmonic excitation activates CO2 is beginning to be understood.