Elucidating how photoexcited semiconductor nanocrystals drive multi-electron redox catalysis
Gordana Dukovic
University of Colorado Boulder, Department of Chemistry
Renewable and Sustainable Energy Institute | Materials Science and Engineering
Date: December 6th, 2022 at 4:00 - 5:00 PM MST
Location: SEEC Building, Room S228 - Sievers Room
Abstract: 
Colloidal semiconductor nanocrystals are remarkably versatile materials with highly tunable electronic structure, optical spectra, and surface properties. My research group works on the photophysics and photochemistry of nanoscale semiconductors with a particular emphasis on light-driven processes involved in multi-electron redox reactions relevant for renewable and sustainable chemical transformations. I will discuss coupling of semiconductor nanocrystals with redox enzymes to photochemically drive reactions such as reduction of H+ to H2, N2 fixation to make NH3, and carbon-carbon bond formation. Using time-resolved spectroscopy over a broad range of timescales (100 fs – 10 μs), in conjunction with kinetic modeling, we examine charge transfer between photoexcited nanocrystals and enzymes to identify structural and chemical parameters that govern the overall photochemical reactivity. I will also describe the dynamics of photoexcited holes in nanocrystals and the implications of those dynamics on oxidation photochemistry. In particular, I will discuss the spatial dynamics of trapped holes on nanocrystal surfaces and the consequences of their behavior on charge transfer.
Bio:
Gordana Dukovic is a professor of chemistry and materials science and engineering and a fellow and associate director of the Renewable and Sustainable Energy Institute at the University of Colorado Boulder. Her research focuses on structure, excited state properties, and light-driven chemistry of nanoscale materials. She received a PhD in chemistry from Columbia University in 2006 and carried out postdoctoral research at the University of California Berkeley (2006-2009). She has received the NSF CAREER Award, and was named a Sloan Research Fellow, a Cottrell Scholar, a Beckman Young Investigator, and a Finalist for the Blavatnik National Award for Young Scientists.