FREE-STANDING WO3 NANOTUBE ARRAY ELECTRODES VIA THE POROUS-ALUMINA-ASSISTED ANODIZING OF W/TI LAYERS

FREE-STANDING WO3 NANOTUBE ARRAY ELECTRODES VIA THE POROUS-ALUMINA-ASSISTED ANODIZING OF W/TI LAYERS

Paper in proceedings (conference paper)

Nanostructured tungsten oxide (TO) exhibits excellent electrochromic, photochromic and gas sensing properties. However, the well-controlled fabrication of stable TO nanofilms remains a challenge. Here we describe an electrochemical approach to synthesize a self-organized array of long aspect ratio TO nanocap-sules, which then can be top-opened and transformed to vertically-aligned, spatial-ly-ordered TO nanotubes. The amorphous array of TO nanocapsules is formed via the initial growth of a nanoporous alumina film, followed by the pore-directed ano-dizing of a W/Ti underlayer. The capsules/tubes may have the diameter of 30-150 nm, the length of up to 800 nm, and the population density of 109 cm-2. A model of porous-alumina-assisted growth of the TO nanotube array is discussed. Electri-cal/dielectric characterization of the TO nanotubes revealed the potential for apply-ing the films as electrodes for photoelectrochemical hydrogen generation, as active layers of gas sensors, micro-diodes and parts of electronic circuits where the well-defined nano-channels for carriers may bring greater advantages.

Nanostructured tungsten oxide (TO) exhibits excellent electrochromic, photochromic and gas sensing properties. However, the well-controlled fabrication of stable TO nanofilms remains a challenge. Here we describe an electrochemical approach to synthesize a self-organized array of long aspect ratio TO nanocap-sules, which then can be top-opened and transformed to vertically-aligned, spatial-ly-ordered TO nanotubes. The amorphous array of TO nanocapsules is formed via the initial growth of a nanoporous alumina film, followed by the pore-directed ano-dizing of a W/Ti underlayer. The capsules/tubes may have the diameter of 30-150 nm, the length of up to 800 nm, and the population density of 109 cm-2. A model of porous-alumina-assisted growth of the TO nanotube array is discussed. Electri-cal/dielectric characterization of the TO nanotubes revealed the potential for apply-ing the films as electrodes for photoelectrochemical hydrogen generation, as active layers of gas sensors, micro-diodes and parts of electronic circuits where the well-defined nano-channels for carriers may bring greater advantages.

tungsten oxide, nanotubes, anodizing, porous anodic alumina, electrical properties, photoelectrochemical water splitting

tungsten oxide, nanotubes, anodizing, porous anodic alumina, electrical properties, photoelectrochemical water splitting

MOZALEV, A.; BENDOVÁ, M.; PYTLÍČEK, Z.; HASSEL, A. W.

2016

01.06.2015

978-80-554-1033-3

Proceedings of the 3rd International Conference on ADVANCES IN ELECTRONIC AND PHOTONIC TECHNOLOGIES (ADEPT2015)

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