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Dye-sensitized TiO2 nanotube membranes act as a visible-light switchable diffusion gate
Imgon Hwang1, Francesca Riboni1,2, Ekaterina Gongadze3
1Department of Materials Science WW4-LKO, University of Erlangen-Nuremberg Martensstrasse 7 91058 Erlangen Germany schmuki@ww.uni-erlangen.de.
Nanoscale Advances
|September 22, 2022
Summary
Dye-sensitized titanium dioxide nanotube membranes act as light-controlled gates. Visible light reversibly opens these gates, increasing flow of molecules and nanospheres through nanofluidic channels.
Area of Science:
- Materials Science
- Nanotechnology
- Physical Chemistry
Background:
- Anodic titanium dioxide (TiO2) nanotube membranes are advanced nanomaterials with tunable properties.
- Controlling molecular transport through nanoporous membranes is crucial for various applications.
Purpose of the Study:
- To develop and investigate optically switchable flow-through gates using dye-sensitized TiO2 nanotube membranes.
- To understand the mechanism behind light-induced changes in membrane permeation.
Main Methods:
- Fabrication of both-end open anodic TiO2 nanotube membranes.
- Sensitization of membranes with a Ruthenium(II)-based dye.
- Characterization of permeation properties under visible light and dark conditions.
- Utilizing nanoprobes (e.g., polystyrene nanospheres) to assess gating capabilities.
- Quantitative modeling to elucidate the switching mechanism.
Main Results:
- Dye-sensitized TiO2 nanotube membranes exhibit reversible visible-light switching properties.
- Illumination opens the gate, increasing small molecule permeation by approximately four times compared to the dark state.
- The gating effect extends to nanoprobes like polystyrene nanospheres.
- No significant dye degradation was observed after repeated switching cycles.
Conclusions:
- Dye-sensitized TiO2 nanotube membranes function as effective optically addressable flow-through gates in nanofluidics.
- The switching mechanism is attributed to light-induced alterations in charge distribution at the dye/TiO2 interface, affecting hydrodynamics.
- These findings open possibilities for light-controlled nanofluidic devices.
