Autor según el artículo: Mozalev, Alexander; Bendova, Maria; Gispert-Guirado, Francesc; Pytlicek, Zdenek; Llobet, Eduard
Departamento: Enginyeria Electrònica, Elèctrica i Automàtica
Autor/es de la URV: Gispert Guirado, Francesc / GUIRADO PAGÉS, FRANCISCO / Llobet Valero, Eduard
Palabras clave: Oxides Nanocapsules Alumina
Resumen: © The Royal Society of Chemistry 2016. An array of highly aligned tungsten-oxide (TO) nanorods, ∼80 nm wide, up to 900 nm long, spatially separated at their bottoms by tungsten metal on a substrate is synthesized via the self-localized anodization of aluminum followed by the porous-alumina-assisted re-anodization of tungsten in a sputter-deposited Al/W bilayer. Moreover, the pore-directed TO nanocapsules may grow, which can be electrochemically top-opened in alumina nanopores and transformed to TO nanotubes, representing unique architectures built up on tungsten substrates to date. The as-grown nanorods are composed of amorphous WO3mixed with minor amounts of WO2and Al2O3in the outer layer and oxide-hydroxide compound (WO3·nH2O) with aluminum tungstate (2Al2O3·5WO3), mainly present inside the rods. Once the growing oxide fills up the pores, it comes out as an array of exotic protuberances of highly hydrated TO, with no analogues among the other valve-metal oxides. Vacuum or air annealing at 550 °C increases the portion of non-stoichiometric oxides 'doped' with OH-groups and gives monoclinic WO2.9or a mixture of WO3and WO2.9nanocrystalline phases, respectively. The nanorods show n-type semiconductor behavior when examined by Mott-Schottky analysis, with a high carrier density of 7 × 1019or 3 × 1019cm-3for the air- or vacuum-annealed samples, associated with a charge depletion layer of about 8 or 10 nm, respectively. A model for the growth of the metal-substrate-separated TO nanocapsules and tubes is proposed and experimentally justified. The findings suggest that the new TO nanoarrays with well-defined nano-channels for carriers may form the basic elements for photoanodes or emerging 3-D micro- and nano-sensors.
Áreas temáticas: Renewable energy, sustainability and the environment Química Odontología Medicina i Materials science, multidisciplinary Materials science (miscellaneous) Materials science (all) Materials science Materials chemistry Materiais Interdisciplinar General materials science General chemistry Farmacia Engenharias iv Engenharias ii Energy & fuels Ciências biológicas ii Ciências biológicas i Ciências agrárias i Chemistry, physical Chemistry (miscellaneous) Chemistry (all) Biotecnología Biodiversidade Astronomia / física
Acceso a la licencia de uso: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 0959-9428
Direcció de correo del autor: eduard.llobet@urv.cat
Identificador del autor: 0000-0001-6164-4342
Página final: 8232
Fecha de alta del registro: 2024-10-12
Volumen de revista: 4
Versión del articulo depositado: info:eu-repo/semantics/publishedVersion
Enlace a la fuente original: https://pubs.rsc.org/en/content/articlelanding/2016/TA/C6TA02027E#!divAbstract
URL Documento de licencia: https://repositori.urv.cat/ca/proteccio-de-dades/
Referencia al articulo segun fuente origial: Journal Of Materials Chemistry a. 4 (21): 8219-8232
Referencia de l'ítem segons les normes APA: Mozalev, Alexander; Bendova, Maria; Gispert-Guirado, Francesc; Pytlicek, Zdenek; Llobet, Eduard (2016). Metal-substrate-supported tungsten-oxide nanoarrays via porous-alumina-assisted anodization: from nanocolumns to nanocapsules and nanotubes. Journal Of Materials Chemistry a, 4(21), 8219-8232. DOI: 10.1039/c6ta02027e
DOI del artículo: 10.1039/c6ta02027e
Entidad: Universitat Rovira i Virgili
Año de publicación de la revista: 2016
Página inicial: 8219
Tipo de publicación: Journal Publications