title: Vacuum template synthesis of multifunctional nanotubes with tailored nanostructured walls.
abstract: A three-step vacuum procedure for the fabrication of vertical TiO2 and ZnO nanotubes with three dimensional walls is presented. The method combines physical vapor deposition of small-molecules, plasma enhanced chemical vapor deposition of inorganic functional thin films and layers and a post-annealing process in vacuum in order to remove the organic template. As a result, an ample variety of inorganic nanotubes are made with tunable length, hole dimensions and shapes and tailored wall composition, microstructure, porosity and structure. The fabrication of multishell nanotubes combining different semiconducting oxides and metal nanoparticles is as well explored. This method provides a feasible and reproducible route for the fabrication of high density arrays of vertically alligned nanotubes on processable substrates. The emptying mechanism and microstructure of the nanotubes have been elucidated through SEM, STEM, HAADF-STEM tomography and energy dispersive X-ray spectroscopy. In this article, as a proof of concept, it is presented the straightforward integration of ZnO nanotubes as photoanode in a photovoltaic cell and as a photonic oxygen gas sensor.
authors: Nanotechnology on Surfaces Laboratory, ICMS Materials Science Institute of Seville (CSIC-US). C/Americo Vespucio 49, 41092, Seville (Spain).
authors: A Nicolas
authors: AN
authors: Filippin
authors: Nanotechnology on Surfaces Laboratory, ICMS Materials Science Institute of Seville (CSIC-US). C/Americo Vespucio 49, 41092, Seville (Spain).
authors: Manuel
authors: M
authors: Macias-Montero
authors: Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, CB3 0FS, Cambridge (United Kingdom).
authors: Zineb
authors: Z
authors: Saghi
authors: Departamento de Sistemas Físicos, Químicos y Naturales Universidad Pablo de Olavide, Carretera de Utrera km1, 41013 Seville (Spain).
authors: Jesús
authors: J
authors: Idígoras
authors: Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, CB3 0FS, Cambridge (United Kingdom).
authors: Pierre
authors: P
authors: Burdet
authors: Nanotechnology on Surfaces Laboratory, ICMS Materials Science Institute of Seville (CSIC-US). C/Americo Vespucio 49, 41092, Seville (Spain).
authors: Angel
authors: A
authors: Barranco
authors: Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, CB3 0FS, Cambridge (United Kingdom).
authors: Paul
authors: P
authors: Midgley
authors: Departamento de Sistemas Físicos, Químicos y Naturales Universidad Pablo de Olavide, Carretera de Utrera km1, 41013 Seville (Spain).
authors: Juan A
authors: JA
authors: Anta
authors: Nanotechnology on Surfaces Laboratory, ICMS Materials Science Institute of Seville (CSIC-US). C/Americo Vespucio 49, 41092, Seville (Spain).
authors: Ana
authors: A
authors: Borras