title: Solar-Driven Water Oxidation and Decoupled Hydrogen Production Mediated by an Electron-Coupled-Proton Buffer.
abstract: Solar-to-hydrogen photoelectrochemical cells (PECs) have been proposed as a means of converting sunlight into H2 fuel. However, in traditional PECs, the oxygen evolution reaction and the hydrogen evolution reaction are coupled, and so the rate of both of these is limited by the photocurrents that can be generated from the solar flux. This in turn leads to slow rates of gas evolution that favor crossover of H2 into the O2 stream and vice versa, even through ostensibly impermeable membranes such as Nafion. Herein, we show that the use of the electron-coupled-proton buffer (ECPB) H3PMo12O40 allows solar-driven O2 evolution from water to proceed at rates of over 1 mA cm(-2) on WO3 photoanodes without the need for any additional electrochemical bias. No H2 is produced in the PEC, and instead H3PMo12O40 is reduced to H5PMo12O40. If the reduced ECPB is subjected to a separate electrochemical reoxidation, then H2 is produced with full overall Faradaic efficiency.
authors.affiliation: WestCHEM School of Chemistry, University of Glasgow , University Avenue, Glasgow G12 8QQ, United Kingdom.
authors.forename: Leanne G
authors.initials: LG
authors.lastname: Bloor
authors.affiliation: Faculty of Chemistry, University of Warsaw , Pasteura 1, 02-093 Warsaw, Poland.|Center of New Technologies, University of Warsaw , S. Banacha 2c, 02-097 Warsaw, Poland.
authors.forename: Renata
authors.initials: R
authors.lastname: Solarska
authors.affiliation: Center of New Technologies, University of Warsaw , S. Banacha 2c, 02-097 Warsaw, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Bienkowski
authors.affiliation: Faculty of Chemistry, University of Warsaw , Pasteura 1, 02-093 Warsaw, Poland.
authors.forename: Pawel J
authors.initials: PJ
authors.lastname: Kulesza
authors.affiliation: Center of New Technologies, University of Warsaw , S. Banacha 2c, 02-097 Warsaw, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Augustynski
authors.affiliation: WestCHEM School of Chemistry, University of Glasgow , University Avenue, Glasgow G12 8QQ, United Kingdom.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Symes
authors.affiliation: WestCHEM School of Chemistry, University of Glasgow , University Avenue, Glasgow G12 8QQ, United Kingdom.
authors.forename: Leroy
authors.initials: L
authors.lastname: Cronin