title: TiO2nanotubes with laterally spaced ordering enable optimized hierarchical structures with significantly enhanced photocatalytic H2generation.
abstract: In the present work we grow self-organized TiO2nanotube arrays with a defined and controlled regular spacing between individual nanotubes. These defined intertube gaps allow one to build up hierarchical 1D-branched structures, conformally coated on the nanotube walls using a layer by layer nanoparticle TiO2decoration of the individual tubes, i.e. having not only a high control over the TiO2nanotube host structure but also on the harvesting layers. After optimizing the intertube spacing, we build host-guest arrays that show a drastically enhanced performance in photocatalytic H2generation, compared to any arrangement of conventional TiO2nanotubes or conventional TiO2nanoparticle layers. We show this beneficial effect to be due to a combination of an increased large surface area (mainly provided by the nanoparticle layers) with a fast transport of the harvested charge within the passivated 1D nanotubes. We anticipate that this type of hierarchical structures based on TiO2nanotubes with adjustable spacing will find even wider application, as they provide an unprecedented controllable combination of surface area and carrier transport.
authors.affiliation: Department of Materials Science and Engineering WW4-LKO, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen, Germany.
authors.forename: Nhat Truong
authors.initials: NT
authors.lastname: Nguyen
authors.affiliation: Department of Materials Science and Engineering WW4-LKO, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen, Germany.
authors.forename: Selda
authors.initials: S
authors.lastname: Ozkan
authors.affiliation: Department of Materials Science and Engineering WW4-LKO, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen, Germany.
authors.forename: Imgon
authors.initials: I
authors.lastname: Hwang
authors.affiliation: Department of Materials Science and Engineering WW4-LKO, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen, Germany.
authors.forename: Anca
authors.initials: A
authors.lastname: Mazare
authors.affiliation: Department of Materials Science and Engineering WW4-LKO, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen, Germany and Chemistry Department, Faculty of Sciences, King Abdulaziz University, 80203 Jeddah, Saudi Arabia Kingdom. schmuki@ww.uni-erlangen.de.
authors.forename: Patrik
authors.initials: P
authors.lastname: Schmuki