Dye-sensitized anodic TiO2 nanotubes

Abstract In this work, we report on dye-sensitization of self-organized TiO 2 nanotubes and the photoelectrochemical response of this system. The tubes were grown by Ti anodization in fluoride containing electrolytes in two different forms as “long” tube (tube lengths ∼ 2.5 μm) and “short” tubes (tube lengths ∼ 500 nm). Both the tube types have a tube diameter of approximately 100 nm and a wall thickness of 15 nm. After annealing the tubes to anatase they were sensitized with Ru-dye (N3) in different concentrations. The results show that apart from the dye concentration also the tube length affects the magnitude of the photocurrent response. For the “long” tubes an IPCE max (at 540 nm) of 3.3% and for the “short tubes” of 1.6% (at 530 nm) are obtained. These results show that self-organized TiO 2 nanotubes can be dye-sensitized in the visible range and a considerable light conversion efficiency can be achieved.

[1]  T. Kitamura,et al.  Enhancement of electron transport in nano-porous TiO2 electrodes by dye adsorption , 2003 .

[2]  Ladislav Kavan,et al.  ELECTROCHEMICAL AND PHOTOELECTROCHEMICAL INVESTIGATION OF SINGLE-CRYSTAL ANATASE , 1996 .

[3]  M. Grätzel Photoelectrochemical cells : Materials for clean energy , 2001 .

[4]  B. Parkinson,et al.  The Adsorption Behavior of a Ruthenium‐Based Sensitizing Dye to Nanocrystalline TiO2 Coverage Effects on the External and Internal Sensitization Quantum Yields , 1999 .

[5]  Eugeniu Balaur,et al.  Tailoring the wettability of TiO2 nanotube layers , 2005 .

[6]  Jan M. Macak,et al.  Self-organized porous titanium oxide prepared in Na2SO4/NaF electrolytes , 2005 .

[7]  Marc Aucouturier,et al.  Anodic oxidation of titanium and TA6V alloy in chromic media. An electrochemical approach , 1999 .

[8]  M. Grätzel,et al.  A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films , 1991, Nature.

[9]  N. M. Iha,et al.  Metal complex sensitizers in dye-sensitized solar cells , 2004 .

[10]  Mohammad Khaja Nazeeruddin,et al.  Conversion of light to electricity by cis-X2bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(II) charge-transfer sensitizers (X = Cl-, Br-, I-, CN-, and SCN-) on nanocrystalline titanium dioxide electrodes , 1993 .

[11]  Craig A. Grimes,et al.  Extreme Changes in the Electrical Resistance of Titania Nanotubes with Hydrogen Exposure , 2003 .

[12]  Patrik Schmuki,et al.  High-aspect-ratio TiO2 nanotubes by anodization of titanium. , 2005, Angewandte Chemie.

[13]  Jan M. Macak,et al.  Titanium oxide nanotubes prepared in phosphate electrolytes , 2005 .

[14]  Craig A. Grimes,et al.  Titanium oxide nanotube arrays prepared by anodic oxidation , 2001 .