Dye-Sensitization for the Production of Electrical Power and Chemical Fuels from Sunlight
Gerald J. Meyer
Department of Chemistry,
University of North Carolina at Chapel Hill, Chapel Hill, NC, USA 27599-3290
Dye-sensitized solar cells have received considerable attention since the advent of mesoporous metal oxide thin films first described by Grätzel and O’Regan . We have a fundamental interest in light driven interfacial electron transfer in these materials that is motivated by applications in electrical power generation and in solar fuels production [1,2]. Background on dye-sensitization and solar energy conversion will be provided that gives context for our most recent advances that suggest new directions for future research. An example includes the identification of a kinetic pathway for electron transfer from TiO2 to transition metal complexes with two redox active groups. [2,3] The distance between the two groups were held near parity yet electron transfer through an aromatic bridge that separated them was critically dependent on the degree of conjugation [3,4]. Electron transfer to acceptors positioned at variable distances from a conductive oxide surface revealed that the intrinsic barriers were dramatically decreased within the electric double layer . Mechanistic study of core/shell oxide materials provided new insights into electron transport that were correlated with water oxidation efficiency . Finally, an alternative approach to solar fuel production with small band gap semiconductors and tandem catalyst hybrids will be presented. This approach forms the basis of a new Department of Energy supported Solar Hub entitled the Center for Hybrid Approaches in Solar Energy to Liquid Fuels (CHASE) .
 “A Low- Cost, High Efficiency Solar Cell Based on the Dye- Sensitized Colloidal TiO2 Films” O’Regan, B.; Grätzel, M. Nature 1991, 353, 737.
 “Perspectives in Dye Sensitization of Nanocrystalline Mesoporous Thin Films” Hu, K.; Sampaio, R.N.; Schneider, J.; Troian-Gautier, L.; Meyer, G.J. J. Am. Chem. Soc. 2020, in press.
 “A Kinetic Pathway for Interfacial Electron Transfer from a Semiconductor to a Molecule” Hu. K.; Blair, A.D.; Piechota, E.J.; Schauer, P.A.; Sampaio, R.N.; Parlane, F.; Meyer, G.J.; Berlinguette, C.P. Nature Chem. 2016, 8, 853-859.
 “Kinetics Teach That Equilibrium Constants Shift Toward Unity with Increased Electronic Coupling” Sampaio, R.N.; Piechota, E.J.; Troian-Gautier, L.; Maurer, A.B.; Berlinguette, C.P., Meyer, G.J. Proc. Nat. Acad. Sci. USA 2018, 115, 7248-7253.
 “Kinetic Evidence that the Solvent Barrier for Electron Transfer is Absent in the Electric Double Layer” Bangle, R.E.; Schneider, J.; Conroy, D.T.; Aramburu-Troselj, B.M.; Meyer, G.J. J. Am. Chem. Soc. 2020, 142, 14940-14946.
 “Electron Localization and Transport in SnO2/TiO2 Mesoporous Thin Films: Evidence for a SnO2/SnxTi1- xO2/TiO2 Structure” James, E.M.; Bennett, M.T.; Bangle, R.E.; Meyer, G.J. Langmuir 2019, 39, 12694-12703.