With this CAREER Award, the Macromolecular, Supramolecular and Nanochemistry Program of the Division of Chemistry is supporting Professor Prashant Jain of the University of Illinois to study the detailed manner in which light energy is converted into chemical energy within metallic materials. This process, if properly understood and controlled, may become a candidate technology for capturing solar energy and for driving energy-intensive processes in the chemical industry with light. Professor Jain aims at preparing strongly light-absorbing materials that can efficiently convert sunlight into chemical energy in fuels. Another effort involves the achievement of light-to-chemical energy conversion using cheaper, more abundant materials. Alongside the laboratory efforts, an interactive software tool is being developed and employed for the purpose of education on the interaction of light with matter. The educational program is aimed at generating early scientific interest in the classroom by means of vivid, hands-on examples from optics, preparing high school, undergraduate, and graduate students for future science and technology careers. Outreach activities seek to foster community awareness of solar energy as a clean, renewable alternative to energy from fossil fuels.
Professor Jain investigates the physicochemical mechanism(s) by which the plasmonic excitation of a noble metal-containing heterostructure induces or catalyzes chemical reactions on the surface of the nanostructure. In this project, a plasmonic heterostructure consisting of Au nanoparticles in contact with a semiconducting oxide (titanium dioxide and zinc oxide) is studied for determining the relative contributions of plasmonic near-field enhancement, hot electron transfer, and photothermal heating in photocatalytic reactions. This research aims to elucidate the mechanistic role of the oxide and assess whether near-field-assisted bandgap or sub-bandgap photoexcitation of carriers in the oxide is responsible for the observed photoactivity, or, whether charge separation across the metal/oxide is a more important contributor. Professor Jain uses single-molecule fluoresence to identify whether the photoreaction takes place on the metal, on the semiconducting oxide, or at the metal/oxide interface. Finally, he explores plasmon excitation-induced photocatalysis in a noble metal-free plasmonic oxide, which represents an interface-free system where plasmonic excitation and semiconductor electronic transitions are localized within the same crystallite.
