Dissertation Defense: Matthew Galazzo, Interdisciplinary Materials Science

DISSERTATION DEFENSE

Matthew Galazzo, Interdisciplinary Materials Science
*under the direction of David Cliffel and Kane Jennings

“Photosystem I:  Biohybrid Devices and Reduction Catalysts for CO2

12.10.24  |  8:00AM |  Buttrick Hall 206

This dissertation presents the use of Photosystem I (PSI) in proof-of-concept solar redox flow battery applications and CO2 electrochemical reduction catalysts. Solar redox flow batteries are typically composed of two photoelectrodes in a two chambered cell separated by an ion exchange membrane. Light is used to charge solutions, which is pumped away for energy storage and pumped back when power is needed. Our device replaces the photoelectrode components with a photoactive PSI membrane and we show that PSI can transfer electrons between solutions, effectively charging them much like a traditional solar redox flow battery. Single channel and double channel systems are detailed.

This work also delves into applications of PSI towards CO2 catalysis. Copper (Cu) is the leading CO2 catalyst due to its propensity towards multi-carbon products, but it requires external potential. PSI has the potential necessary for electrochemical CO2 reduction but is not CO2 active. We show 3 ways of coupling PSI to Cu:  1) growing Cu by photoreduction directly from PSI 2) attaching a pre-synthesized Cu nanoparticle to PSI and 3) orienting PSI on a Cu electrode. To our knowledge, these works are the first use of PSI towards CO2 reduction and the first to couple Cu nanoparticles to PSI.