The influence of the mixed phase (Ti–TiO2(A): TiO2(R)) on the optical band gap of TiO2 nanotubes heat treated at different temperatures
Highly ordered TiO 2 nanotubes (NTs) were synthesized by electrochemical anodization than annealed at different temperatures between 300 and 900 °C for 3 h. The elaborated NTs adhere well to the Ti substrate over the annealing temperature range of 300–600 °C. The TiO 2 NTs morphology begins to gradu...
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Published in | Journal of materials research Vol. 38; no. 14; pp. 3446 - 3457 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Cham
Springer International Publishing
28.07.2023
Springer Nature B.V Springer |
Subjects | |
Online Access | Get full text |
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Summary: | Highly ordered TiO
2
nanotubes (NTs) were synthesized by electrochemical anodization than annealed at different temperatures between 300 and 900 °C for 3 h. The elaborated NTs adhere well to the Ti substrate over the annealing temperature range of 300–600 °C. The TiO
2
NTs morphology begins to gradually evolve for temperatures up to 700 °C and approaches that of nanoparticles until the latter become predominant at T above 800 °C. Reflection measurements show that the NTs present reflection of 7% at 600 °C, corresponding to the lowest band gap 2.59 eV. This can be related to the presence of the mixed phase (Ti–TiO
2(A)
–TiO
2(R))
.The charge carrier density decreases from 2.34 × 10
+21
to 3.61 × 10
+13
cm
−3
when the annealing temperature increases, that accompanied by a reduction in the resistivity from 142.23 to 29.56Ω.cm which is adequate to photo anode application.
Graphical abstract |
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ISSN: | 0884-2914 2044-5326 |
DOI: | 10.1557/s43578-023-01027-4 |