title: Engineering titania nanostructure to tune and improve its photocatalytic activity.
abstract: Photocatalytic pathways could prove crucial to the sustainable production of fuels and chemicals required for a carbon-neutral society. Electron-hole recombination is a critical problem that has, so far, limited the efficiency of the most promising photocatalytic materials. Here, we show the efficacy of anisotropy in improving charge separation and thereby boosting the activity of a titania (TiO2) photocatalytic system. Specifically, we show that H2 production in uniform, one-dimensional brookite titania nanorods is highly enhanced by engineering their length. By using complimentary characterization techniques to separately probe excited electrons and holes, we link the high observed reaction rates to the anisotropic structure, which favors efficient carrier utilization. Quantum yield values for hydrogen production from ethanol, glycerol, and glucose as high as 65%, 35%, and 6%, respectively, demonstrate the promise and generality of this approach for improving the photoactivity of semiconducting nanostructures for a wide range of reacting systems.
authors.affiliation: Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104; Department of Chemical Engineering, Stanford University, Stanford, CA 94305; SUNCAT Center for Interface Science and Catalysis, Stanford University, Stanford, CA 94305;
authors.forename: Matteo
authors.initials: M
authors.lastname: Cargnello
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, Institute of Chemistry of Organometallic Compounds, National Research Council (CNR), National Interuniversity Consortium of Materials Science and Technology (INSTM), University of Trieste, 34127 Trieste, Italy;
authors.forename: Tiziano
authors.initials: T
authors.lastname: Montini
authors.affiliation: Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104;
authors.forename: Sergey Y
authors.initials: SY
authors.lastname: Smolin
authors.affiliation: Leibniz-Institut für Katalyse e.V., Universität Rostock, 18059 Rostock, Germany;
authors.forename: Jacqueline B
authors.initials: JB
authors.lastname: Priebe
authors.affiliation: Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Spain;
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Delgado Jaén
authors.affiliation: Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Vicky V T
authors.initials: VV
authors.lastname: Doan-Nguyen
authors.affiliation: Department of Chemical Engineering, Stanford University, Stanford, CA 94305; SUNCAT Center for Interface Science and Catalysis, Stanford University, Stanford, CA 94305;
authors.forename: Ian S
authors.initials: IS
authors.lastname: McKay
authors.affiliation: Department of Chemical Engineering, Stanford University, Stanford, CA 94305; SUNCAT Center for Interface Science and Catalysis, Stanford University, Stanford, CA 94305;
authors.forename: Jay A
authors.initials: JA
authors.lastname: Schwalbe
authors.affiliation: Leibniz-Institut für Katalyse e.V., Universität Rostock, 18059 Rostock, Germany;
authors.forename: Marga-Martina
authors.initials: MM
authors.lastname: Pohl
authors.affiliation: Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104;
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Gordon
authors.affiliation: Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104;
authors.forename: Jason B
authors.initials: JB
authors.lastname: Baxter
authors.affiliation: Leibniz-Institut für Katalyse e.V., Universität Rostock, 18059 Rostock, Germany;
authors.forename: Angelika
authors.initials: A
authors.lastname: Brückner
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, Institute of Chemistry of Organometallic Compounds, National Research Council (CNR), National Interuniversity Consortium of Materials Science and Technology (INSTM), University of Trieste, 34127 Trieste, Italy;
authors.forename: Paolo
authors.identifier: http://orcid.org/0000-0003-1082-9157
authors.initials: P
authors.lastname: Fornasiero
authors.affiliation: Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104; Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104 cbmurray@sas.upenn.edu.
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Murray
keywords: brookite; hydrogen; photocatalysis; photoreforming; titania