Electrical and Proton Conduction Properties of Amorphous TiO₂ Nanotubes Fabricated by Electrochemical Anodization

Abstract

Electrolyte contacts were used to investigate the properties of pure and N-doped titania nanotubes (ntTiO 2 ). Mott-Schottky analysis gave a flat-band potential E fb = -0.57V vs. Ag/AgCl for pure ntTiO 2 and E fb = -0.22V vs. Ag/AgCl for N-doped ntTiO 2 . The charge carrier density was N D = 6.7 10 20 cm -3 for pure ntTiO 2 and N D = 3.9 10 20 for N-doped ntTiO 2 . This investigation also allowed estimation of the apparent diffusion coefficient of H + in ntTiO 2 . Following the Randles-Sevcik method, the effective proton diffusion coefficient in ntTiO 2 is (2±1)·10 -11 cm 2 s -1 while in Ndoped ntTiO 2 it is (4±1)·10 -11 cm 2 s -1 . Using the Warburg diffusion element determined by electrochemical impedance spectroscopy, the proton diffusion coefficient is (2±1)·10 -11 cm 2 s -1 for pure ntTiO 2 while for nitrogen-doped ntTiO 2 a value of (7±3)·10 -11 cm 2 s -1 is found. These values are consistent with those of the RandlesSevcik method.

A Study on Doped Heterojunctions in TiO2 Nanotubes: An Efficient Photocatalyst for Solar Water Splitting

“…9b . The peaks are positioned around 398.7 in all the samples which correspond to doped nitrogen, which is consistent with our previous report and other reports found in literature 65 – 68 . The N 1s peak intensity gradually increases from NT-0.5 to NT-4.5 which confirms that the quantity of nitrogen doping in TiO 2 crystal increases with increase in hydrazine hydrate concentration.…”

Nanostructured Ceramics: Ionic Transport and Electrochemical Activity

“…Bereitgestellt von | Technische Universität Graz Angemeldet Heruntergeladen am | 10.08. 17 20:05 species such as H + [60], Li + [40] and Na + [42] pertaining to the broader field of energy storage and conversion. Whereas earlier NMR studies focused on Li ion diffusion in crystalline nanotubes of TiO 2 , mainly TiO 2 -B, that were prepared by hydrothermal routes, so far less information is available on Li + ion dynamics in amorphous titania nanotubes.…”

Two-dimensional photonic crystals based on anodic porous TiO2 with ideally ordered hole arrangement

“…However, the free carriers in TiO 2 do not affect the properties of the photonic crystal because the free carrier density in TiO 2 is relatively low (∼10 20 cm −3 ). 22) Figure 6 shows the photonic band gap calculated for the hole array structure using a plane wave expansion method. A common band gap for the Γ-X and Γ-J propagation directions was obtained for the wavelength range of 490-525 nm.…”