title: Control of Electrons' Spin Eliminates Hydrogen Peroxide Formation During Water Splitting.
abstract: The production of hydrogen through water splitting in a photoelectrochemical cell suffers from an overpotential that limits the efficiencies. In addition, hydrogen-peroxide formation is identified as a competing process affecting the oxidative stability of photoelectrodes. We impose spin-selectivity by coating the anode with chiral organic semiconductors from helically aggregated dyes as sensitizers; Zn-porphyrins and triarylamines. Hydrogen peroxide formation is dramatically suppressed, while the overall current through the cell, correlating with the water splitting process, is enhanced. Evidence for a strong spin-selection in the chiral semiconductors is presented by magnetic conducting (mc-)AFM measurements, in which chiral and achiral Zn-porphyrins are compared. These findings contribute to our understanding of the underlying mechanism of spin selectivity in multiple electron-transfer reactions and pave the way toward better chiral dye-sensitized photoelectrochemical cells.
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science , Rehovot 76100, Israel.
authors.forename: Wilbert
authors.initials: W
authors.lastname: Mtangi
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science , Rehovot 76100, Israel.
authors.forename: Francesco
authors.initials: F
authors.lastname: Tassinari
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science , Rehovot 76100, Israel.
authors.forename: Kiran
authors.initials: K
authors.lastname: Vankayala
authors.affiliation: Institute for Complex Molecular Systems, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
authors.forename: Andreas
authors.identifier: 0000-0003-1386-3174
authors.initials: A
authors.lastname: Vargas Jentzsch
authors.affiliation: Institute for Complex Molecular Systems, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Adelizzi
authors.affiliation: Institute for Complex Molecular Systems, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
authors.forename: Anja R A
authors.initials: AR
authors.lastname: Palmans
authors.affiliation: Department of Engineering, University of Modena and Reggio Emilia , Via Vivarelli 10, 41125 Modena, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Fontanesi
authors.affiliation: Institute for Complex Molecular Systems, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
authors.forename: E W
authors.identifier: 0000-0003-4126-7492
authors.initials: EW
authors.lastname: Meijer
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science , Rehovot 76100, Israel.
authors.forename: Ron
authors.initials: R
authors.lastname: Naaman