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Session G23: Invited Session: Fuels From Sunlight: Computational Studies of Photo-Electrodes and Catalysts

11:15 AM–2:15 PM, Tuesday, March 4, 2014
Room: 505-507

Sponsoring Unit: DCOMP
Chair: Giulia Galli, University of California, Davis

Abstract ID: BAPS.2014.MAR.G23.3

Abstract: G23.00003 : Cobalt, nickel/iron, and titanium oxide electrodes for water oxidation*

12:27 PM–1:03 PM

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Author:

Annabella Selloni
(Princeton University)

Water splitting on metal oxide surfaces has attracted enormous interest for more than forty years. While a great deal of work has focused on titanium dioxide (TiO$_{\mathrm{2}})$, recently cobalt and mixed Ni-Fe oxides have also emerged as promising electrocatalysts for water oxidation due to their low cost and high activity. In this talk I shall discuss various aspects of water oxidation on cobalt (hydro-)oxides, pure and mixed nickel and iron (hydro-)oxides, and TiO$_{\mathrm{2\thinspace }}$surfaces. Using DFT$+$U calculations, I shall examine the composition and structure of cobalt and Ni-Fe oxides under electrochemical conditions, and present studies of the oxygen evolution reaction (OER) on the relevant stable compounds. I shall also present hybrid functional calculations of the first proton-coupled-electron transfer at the water/TiO$_{\mathrm{2}}$ interface in the presence of a photoexcited hole. Our results provide evidence that the proton and electron transfers are not concerted but rather represent two sequential processes. They also suggest that the OER is faster at higher pH, as indeed observed experimentally.

*This work was supported by DoE-BES, Division of Chemical Sciences, Geosciences and Biosciences under Award DE-FG02-12ER16286.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2014.MAR.G23.3