Titre : Earth-Abundant Photoelectrodes for Solar Fuels Catalysis
Endroit: Pavillon Roger-Gaudry, Salle G-715
Hôte : Prof. Hanan Garry
Harnessing sunlight to drive chemical transformations, or to store the sun’s energy in chemical bonds (solar “fuels” generation), begins with the development of molecules and materials capable of capturing visible light and converting that light into separated charge carriers. To this end, our lab has been working towards developing and optimizing functionalized nanostructured semiconductor surfaces that act as the working electrode in sensitized photoelectrochemical cells. Charge separation processes within such nanohybrid architectures are analogous to the first steps of the electron transfer cascade observed in natural photosynthesis, where light absorption generates redox equivalents that are shuttled to catalytic sites. Several criteria must be met for this type of device to work efficiently including the incorporation of molecular light absorbing chromophores that can deliver multiple redox equivalents to molecular catalysts at rates exceeding those of charge recombination within the cell. Highlighted in this lecture are our recent efforts to functionalize oriented zinc oxide nanowires with purpose-synthesized Cu(I)-based donor-chromophore-acceptor triads and carbon dots. In the former, redox leveling across all components of the molecular system enable it to drive a molecular water oxidation catalyst on photoexcitation, while in the latter, white light irradiation is used to drive a-heteroarylation reactions of tertiary amines.
Biography : Marek B. Majewski is an Assistant Professor of Chemistry at Concordia University (Montréal). As a postdoctoral research fellow and Assistant Director of Operations at the Argonne-Northwestern Solar Energy Research (ANSER) Center and Northwestern University he worked together with Prof. Michael R. Wasielewski, Prof. Joseph T. Hupp and Prof. Omar K. Farha on photoinitiated charge separation and transport to drive molecular solar fuels catalysts and the design of functional inorganic materials. He completed his Honours B.Sc. in 2007 at the University of Saskatchewan followed by his Ph.D. degree under the mentorship of Prof. Michael O. Wolf at the University of British Columbia in 2013.