Controllable current oscillation and pore morphology evolution in the anodic growth of TiO2 nanotubes

The spatial heterogeneities and temporal instabilities in the anodic growth of TiO₂ tubes are very important for nanostructure fabrication, but few ordered cases have been reported. In this work, we represent a new current oscillation with pore morphology evolution in the formation of anodic TiO₂ tubes. Small (less than 8.0% of the minimum value) and fast (period ~10⁰ s) current oscillation was formed under static conditions in a wide range, while significant morphological change such as periodical narrowing, abruption and small pits appeared in the pore with characteristic length scale of 10¹-10² nm. Surprisingly, the roughness in the pore would be totally eliminated instead of being enhanced by high speed stirring or periodically modulated voltage with the current oscillation still being enhanced, which indicates an important involvement of the ion transport process. It has also been found that the growth rate could be significantly accelerated by tuning the stirring rate or the periodical modulation of the voltage. The mechanism has been described with consideration of the local reactions and the ion transport with a key involvement of the convection process, which can be strongly influenced by the mechanical stirring and the modulated voltage.

[1]  Andrei Ghicov,et al.  Self-ordering electrochemistry: a review on growth and functionality of TiO2 nanotubes and other self-aligned MO(x) structures. , 2009, Chemical communications.

[2]  J. Macák,et al.  Multilayer TiO2–Nanotube Formation by Two-Step Anodization , 2007 .

[3]  A. Fujishima,et al.  Electrochemical Photolysis of Water at a Semiconductor Electrode , 1972, Nature.

[4]  H. Haken.  Synergetics: Introduction and Advanced Topics , 2004 .

[5]  Peter Greil,et al.  Hydroxyapatite growth on anodic TiO2 nanotubes. , 2006, Journal of biomedical materials research. Part A.

[6]  Patrik Schmuki,et al.  Self-organized TiO2 nanotube layers as highly efficient photocatalysts. , 2007, Small.

[7]  Kouji Yasuda,et al.  Control of morphology and composition of self-organized zirconium titanate nanotubes formed in (NH4)2SO4/NH4F electrolytes , 2007 .

[8]  J. Macák,et al.  250 µm long anodic TiO2 nanotubes with hexagonal self‐ordering , 2007 .

[9]  Jan M. Macak,et al.  Anodic growth of self-organized anodic TiO2 nanotubes in viscous electrolytes , 2006 .

[10]  M. S. Hegde,et al.  Synthesis and structure of nanocrystalline TiO2 with lower band gap showing high photocatalytic activity. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[11]  Zhiqun Lin,et al.  Freestanding TiO2 Nanotube Arrays with Ultrahigh Aspect Ratio via Electrochemical Anodization , 2008 .

[12]  Kenji Fukuda,et al.  Ordered Metal Nanohole Arrays Made by a Two-Step Replication of Honeycomb Structures of Anodic Alumina , 1995, Science.

[13]  Patrik Schmuki,et al.  Influence of Water Content on the Growth of Anodic TiO2 Nanotubes in Fluoride-Containing Ethylene Glycol Electrolytes , 2010 .

[14]  Ulrich Gösele,et al.  Spontaneous Current Oscillations during Hard Anodization of Aluminum under Potentiostatic Conditions , 2010 .

[15]  Jan M. Macak,et al.  Voltage Oscillations and Morphology during the Galvanostatic Formation of Self-Organized TiO2 Nanotubes , 2006 .

[16]  Eugeniu Balaur,et al.  Wetting behaviour of layers of TiO2 nanotubes with different diameters , 2005 .

[17]  Marc Aucouturier,et al.  Structure and physicochemistry of anodic oxide films on titanium and TA6V alloy , 1999 .

[18]  Craig A. Grimes,et al.  A new benchmark for TiO2 nanotube array growth by anodization , 2007 .

[19]  P. Schmuki,et al.  Growth of aligned TiO2 bamboo-type nanotubes and highly ordered nanolace. , 2008, Angewandte Chemie.

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

[21]  Michihiko Kitao,et al.  Preparation and Electrochromism of RF-Sputtered TiO2 Films , 1997 .

[22]  P. Schmuki,et al.  Modulated TiO2 nanotube stacks and their use in interference sensors , 2010 .

[23]  P. Kajitvichyanukul,et al.  Formation and characterization of self-organized TiO2 nanotube arrays by pulse anodization. , 2008, Journal of the American Chemical Society.

[24]  P. Schmuki,et al.  Bamboo-type TiO2 nanotubes: improved conversion efficiency in dye-sensitized solar cells. , 2008, Journal of the American Chemical Society.

[25]  Craig A. Grimes,et al.  TiO2 Nanotube Arrays: Synthesis, Properties, and Applications , 2009 .

[26]  Jan M. Macak,et al.  Smooth anodic TiO2 nanotubes. , 2005, Angewandte Chemie.

[27]  J. Macák,et al.  Mechanistic aspects and growth of large diameter self-organized TiO2 nanotubes , 2008 .

[28]  Chad A Mirkin,et al.  On-Wire Lithography , 2005, Science.

[29]  Kouji Yasuda,et al.  Mechanistic Aspects of the Self-Organization Process for Oxide Nanotube Formation on Valve Metals , 2007 .

[30]  Craig A Grimes,et al.  Use of highly-ordered TiO(2) nanotube arrays in dye-sensitized solar cells. , 2006, Nano letters.

[31]  Andrei Ghicov,et al.  Self-organized, free-standing TiO2 nanotube membrane for flow-through photocatalytic applications. , 2007, Nano letters.

[32]  G. Thompson,et al.  Influence of water content on nanotubular anodic titania formed in fluoride/glycerol electrolytes , 2009 .

[33]  W. Shen,et al.  The large diameter and fast growth of self-organized TiO2 nanotube arrays achieved via electrochemical anodization , 2010, Nanotechnology.

[34]  Kouji Yasuda,et al.  TiO2 nanotubes: Self-organized electrochemical formation, properties and applications , 2007 .

[35]  Gerhard Ertl,et al.  Oscillatory Kinetics in Heterogeneous Catalysis , 1995 .

[36]  W. Hoffmann,et al.  Capillary batch injection analysis: a novel approach for analyzing nanoliter samples , 1998 .

[37]  P. Schmuki,et al.  Gravity assisted growth of self-organized anodic oxide nanotubes on titanium , 2008 .

[38]  Shougang Chen,et al.  Anodic formation of ordered and bamboo-type TiO2 anotubes arrays with different electrolytes , 2010 .

[39]  Zhipeng Huang,et al.  Extended arrays of vertically aligned sub-10 nm diameter [100] Si nanowires by metal-assisted chemical etching. , 2008, Nano letters.

[40]  Craig A. Grimes,et al.  Anodic Growth of Highly Ordered TiO2 Nanotube Arrays to 134 μm in Length , 2006 .