title: H₂ mapping on Pt-loaded TiO₂ nanotube gradient arrays.
abstract: We describe a rapid screening technique for determining the optimal characteristics of nanophotocatalysts for the production of H2 on a single surface. Arrays of TiO2 nanotubes (NTs) with a gradient in length and diameter were fabricated by bipolar anodization, and a perpendicular gradient of Pt nanoparticles (NPs) was generated by the toposelective decoration of the TiO2 NTs. Photocatalytic hydrogen evolution was locally triggered with a UV laser beam, and the arrays were screened in the x and y directions for spatially resolved kinetic measurements and the mapping of the optimal hydrogen production. By using this technique, we demonstrate the time-efficient and straightforward determination of the tube dimensions and Pt loading for optimized H2 production. The concept holds promise for generally improving the study of many photoreactions as a function of the physicochemical characteristic of nanophotocatalysts, which renders it highly attractive for the optimization of various important chemical processes.
authors.affiliation: Department of Materials Science WW-4, LKO, University of Erlangen-Nuremberg , Martensstrasse 7, 91058 Erlangen, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Loget
authors.forename: P
authors.initials: P
authors.lastname: Schmuki