Abstract
TiO2 nanotubes (8-20 nm outer diam. and 3-5 nm inner diam.) grown via alk. hydrothermal synthesis are characterized and compared to 6 nm diam. TiO2 (anatase) nanoparticles. Zeta potential, voltammetric, and titrn. expts. reveal that, in contrast to anatase nanoparticles (p.z.c. .apprx.6), TiO2 nanotubes carry a stronger neg. surface charge (p.z.c. .apprx.3, acidic protons .apprx.2 * 10-3 mol g-1, electrostatic cation adsorption sites in neutral soln. .apprx.7 * 10-5 mol g-1) and, under neutral conditions, offer electrostatic binding sites for cations. When immobilized onto an inert B-doped diamond substrate, TiO2 nanotubes show electrochem. reactivity due to reversible Ti(IV) redn., which is very similar to that obsd. for anatase nanoparticles. Three cationic redox systems, Meldola's blue, Ni2+, and cytochrome c, are immobilized on the TiO2 nanotube surface; the binding ability and the no. of binding sites are quantified voltammetrically. Redox proteins, such as cytochrome c, adsorb readily and irreversibly. Well-defined voltammetric signals for the immobilized protein are obsd. in an aq. buffer. TiO2 nanotubes are novel, inert substrates for both inorg. and biol. electrocatalysts. [on SciFinder (R)]
Original language | English |
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Pages (from-to) | 1050-1058 |
Number of pages | 9 |
Journal | Electrochemistry Communications |
Volume | 7 |
Issue number | 10 |
Publication status | Published - 2005 |
Keywords
- Surface structure (of titania nanotubes)
- Chemically modified electrodes (titania immobilized on boron-doped diamond)
- Catalysts (electrocatalysts
- Nanotubes (titania
- Adsorption
- nickel ion adsorption cyclic voltammetry titania nanotube
- titania nanotubes immobilized on B-doped diamond substrate for electrocatalysts and bioelectrocatalysts)
- Meldola blue adsorption cyclic voltammetry titania nanotube immobilized diamond
- titania nanotube immobilized boron doped diamond electrocatalysis bioelectrocatalysis
- titania nanotubes immobilized on B-doped diamond substrate for electrocatalysis and bioelectrocatalysis)
- cytochrome c adsorption cyclic voltammetry titania nanotube immobilized diamond
- Cyclic voltammetry (of cytochrome c and Meldola's blue and Ni2+ ion on titania nanotubes immobilized on B-doped diamond substrate)