Self-Organized TiO₂ Nanotube Arrays: Synthesis by Anodization in an Ionic Liquid and Assessment of Photocatalytic Properties

Abstract

Self-organized TiO(2) nanotube (NT) arrays were produced by anodization in ethylene glycol (EG) electrolytes containing 1-n-butyl-3-methyl-imidazolium tetrafluoroborate (BMI.BF(4)) ionic liquid and water. The morphology of the as-formed NTs was considerably affected by changing the anodization time, voltage, and water and ionic liquid electrolyte concentrations. In general, a nanoporous layer was formed on the top surface of the TiO(2) NTs, except for anodization at 100 V with 1 vol % of BMI.BF(4), where the NT's mouth was revealed. The length and bottom diameter of the NTs as well as the pore diameter of the top layer showed a linear relationship with increased anodization voltage. These TiO(2) NTs were tested as photocatalysts for methyl orange photodegradation and hydrogen evolution from water/methanol solutions by UV light irradiation. The results show that the TiO(2) NTs obtained by anodization in EG/H(2)O/BMI.BF(4) electrolytes are active and efficient for both applications.

Hybrid tantalum oxide nanoparticles from the hydrolysis of imidazolium tantalate ionic liquids: efficient catalysts for hydrogen generation from ethanol/water solutions

“…9 ILs have thus been used for the generation of various Ti-based nanomaterials [10][11][12][13] with high specific areas and the consequent enhancement of photocatalytic activities. 14 It is reasonable to assume that the structural directionality imposed by the IL can be more effective in the generation of structured nanomaterials if the metal oxide precursor is the IL itself. Moreover, the nanomaterials formed in this way may have a hybrid-like structure with the "chemical and/or physical" incorporation of the IL cation on the metal-oxide.…”

On the formation of anisotropic gold nanoparticles by sputtering onto a nitrile functionalised ionic liquid

“…6 Among all employed PVD methods to prepare colloidal NPs, sputtering deposition onto ionic liquids (ILs) has several advantages since its versatility allows a good control over the size and size distribution of the NPs, 7,8 which is of great importance for special applications. [9][10][11][12][13][14] Moreover, in the case of sputtering deposition onto ILs, very stable spherical NPs are easily prepared by simply adjusting the physical parameters during the sputtering process, allowing for control of the NPs size and size distribution without the addition of extra stabilisers. 15 However, the factors that govern NPs growth in the sputtering process are still unclear.…”

Photosensitised Degradation of Organic Dyes by Visible Light Using Riboflavin Adsorbed on the Surface of TiO2Nanotubes

“…TiO 2 NTs were annealed at 400 °C for 3 h in air atmosphere to obtain the anatase phase. 47,49,51 Finally, TiO 2 NTs were impregnated with RF. The inset of Figure 1-top shows that after RF impregnation, the SEM image of the NTs is blurred and the visualisation of the NTs structure is not clear.…”

“…[47][48][49] After anodisation, the TiO 2 NTs were annealed at 400 °C for 3 h in air atmosphere in order to crystallise the oxide nanotubes layer. The nanotube structures were characterised by scanning electron microscopy (SEM) obtained with EVO50-Carl Zeiss equipment.…”