Light-assisted anodized TiO₂ nanotube arrays.

Self-assembled arrays of titania nanotubes are synthesized via electrochemical anodization of Ti foils under the presence of UV-vis irradiation. Compared to control samples (anodized without light), the light-assisted anodized samples exhibit larger diameters as well as thicker nanotube walls, whereas the length of the nanotubes remains the same under otherwise similar synthesis conditions. Enhanced photoelectrochemical performance with light-assisted anodized samples under simulated AM 1.5 irradiation is observed by an increase in photocurrent density of 45-73% at 1.23 V (RHE). The enhanced photoelectrochemical performance is correlated to improved charge separation analyzed by Mott-Schottky. A mechanism on the photoeffect during anodization is presented. The morphology and improved properties obtained from the synthesis methodology may also find application in other fields such as sensing and catalysis.

[1]  V. Subramanian,et al.  Improved photocatalytic degradation of textile dye using titanium dioxide nanotubes formed over titanium wires. , 2009, Environmental science & technology.

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

[3]  S. D. Collins,et al.  Porous silicon formation mechanisms , 1992 .

[4]  Dong Yang,et al.  Carbon and Nitrogen Co-doped TiO2 with Enhanced Visible-Light Photocatalytic Activity , 2007 .

[5]  Krishnan S. Raja,et al.  Hydrogen generation under sunlight by self ordered TiO2 nanotube arrays , 2009 .

[6]  Y. Nakato,et al.  Photo-oxidation reaction of water on an n-TiO2 electrode. Improvement in efficiency through formation of surface micropores by photo-etching in H2SO4 , 1995 .

[7]  A. Bard,et al.  Novel carbon-doped TiO2 nanotube arrays with high aspect ratios for efficient solar water splitting. , 2006, Nano letters.

[8]  M. Misra,et al.  Electrochemically assisted photocatalytic degradation of methyl orange using anodized titanium dioxide nanotubes , 2008 .

[9]  Y. R. Smith,et al.  Heterostructural Composites of TiO2 Mesh−TiO2 Nanoparticles Photosensitized with CdS: A New Flexible Photoanode for Solar Cells , 2011 .

[10]  Nageh K. Allam,et al.  TiO₂ nanotube-based dye-sensitized solar cell using new photosensitizer with enhanced open-circuit voltage and fill factor. , 2012, ACS applied materials & interfaces.

[11]  Bo Chen,et al.  Influence of patterned concave depth and surface curvature on anodization of titania nanotubes and alumina nanopores. , 2011, Langmuir : the ACS journal of surfaces and colloids.

[12]  Allen J. Bard,et al.  Electrochemical Methods: Fundamentals and Applications , 1980 .

[13]  P. Schmuki,et al.  Morphological instability leading to formation of porous anodic oxide films. , 2011, Nature materials.

[14]  Mano Misra,et al.  Dye-sensitized photovoltaic wires using highly ordered TiO2 nanotube arrays. , 2010, ACS nano.

[15]  Steve Trigwell,et al.  Enhancement of the photoelectrochemical conversion efficiency of nanotubular TiO2 photoanodes using nitrogen plasma assisted surface modification , 2009, Nanotechnology.

[16]  V. K. Mahajan,et al.  Photo-electrochemical hydrogen generation using band-gap modified nanotubular titanium oxide in solar light , 2006 .

[17]  M. Misra,et al.  Templated growth of cadmium zinc telluride (CZT) nanowires using pulsed-potentials in hot non-aqueous solution , 2006 .

[18]  A. Manivannan,et al.  CO2 photoreduction in the liquid phase over Pd-supported on TiO2 nanotube and bismuth titanate photocatalysts , 2011 .

[19]  P. Schmuki,et al.  Transparent TiO2 nanotube electrodes via thin layer anodization: fabrication and use in electrochromic devices. , 2009, Langmuir : the ACS journal of surfaces and colloids.

[20]  Zhonghai Zhang,et al.  Hierarchical top-porous/bottom-tubular TiO2 nanostructures decorated with Pd nanoparticles for efficient Photoelectrocatalytic decomposition of synergistic pollutants. , 2012, ACS applied materials & interfaces.

[21]  M. Misra,et al.  Formation of TiO2-WO3 nanotubular composite via single-step anodization and its application in photoelectrochemical hydrogen generation , 2012 .

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

[23]  Yue Liu,et al.  The fabrication and characterization of novel carbon doped TiO2 nanotubes, nanowires and nanorods with high visible light photocatalytic activity , 2009, Nanotechnology.

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

[25]  V. K. Mahajan,et al.  Design of a Highly Efficient Photoelectrolytic Cell for Hydrogen Generation by Water Splitting: Application of TiO2-xCx Nanotubes as a Photoanode and Pt/TiO2 Nanotubes as a Cathode , 2007 .

[26]  V. Subramanian,et al.  Investigation of Physicochemical Parameters That Influence Photocatalytic Degradation of Methyl Orange over TiO2 Nanotubes , 2009 .

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

[28]  Lionel Vayssieres,et al.  On solar hydrogen & nanotechnology , 2010 .

[29]  W. Smyrl,et al.  Photoelectrochemical investigations of thin metal-oxide films : TiO2, Al2O3, and HfO2 on the parent metals , 1993 .

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

[31]  Th. Dittrich,et al.  Electron Drift Mobility in Porous TiO2 (Anatase) , 1998 .

[32]  Y. R. Smith,et al.  Hydrothermal Synthesis of Bi12TiO20 Nanostrucutures Using Anodized TiO2 Nanotubes and Its Application in Photovoltaics , 2010 .

[33]  V. K. Mahajan,et al.  Determination of photo conversion efficiency of nanotubular titanium oxide photo-electrochemical cell for solar hydrogen generation , 2006 .

[34]  Prajna P. Das,et al.  Synthesis of Coupled Semiconductor by Filling 1D TiO2 Nanotubes with CdS , 2008 .

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

[36]  Patrik Schmuki,et al.  TiO2 nanotubes and their application in dye-sensitized solar cells. , 2010, Nanoscale.

[37]  Aicheng Chen,et al.  Coadsorption of horseradish peroxidase with thionine on TiO2 nanotubes for biosensing. , 2005, Langmuir : the ACS journal of surfaces and colloids.

[38]  I. Vrublevsky,et al.  Effect of the current density on the volume expansion of the deposited thin films of aluminum during porous oxide formation , 2003 .

[39]  Sungho Jin,et al.  Significantly accelerated osteoblast cell growth on aligned TiO2 nanotubes. , 2006, Journal of biomedical materials research. Part A.

[40]  M. Misra,et al.  Effect of water content of ethylene glycol as electrolyte for synthesis of ordered titania nanotubes , 2007 .

[41]  Lihong Zhang,et al.  A study on the oxidation and carbon diffusion of TiC in alumina–titanium carbide ceramics using XPS and Raman spectroscopy , 1998 .

[42]  Jan M. Macak,et al.  TiO2 nanotubes: H+insertion and strong electrochromic effects , 2006 .

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

[44]  Karumbaiah N. Chappanda,et al.  Site-specific and patterned growth of TiO2 nanotube arrays from e-beam evaporated thin titanium film on Si wafer , 2012, Nanotechnology.

[45]  Krishnan S. Raja,et al.  Formation of self-ordered nano-tubular structure of anodic oxide layer on titanium , 2005 .

[46]  M. Misra,et al.  Functionalization of self-organized TiO2 nanotubes with Pd nanoparticles for photocatalytic decomposition of dyes under solar light illumination. , 2008, Langmuir : the ACS journal of surfaces and colloids.

[47]  R. G. Breckenridge,et al.  Electrical properties of titanium dioxide semiconductors , 1950 .

[48]  Krishnan S. Raja,et al.  Electrodeposition of hydroxyapatite onto nanotubular TiO2 for implant applications , 2006 .

[49]  H. Kisch,et al.  Daylight photocatalysis by carbon-modified titanium dioxide. , 2003, Angewandte Chemie.

[50]  V. Subramanian,et al.  CdSe Nanocrystal Assemblies on Anodized TiO2 Nanotubes: Optical, Surface, and Photoelectrochemical Properties , 2012 .

[51]  Lothar Frey,et al.  Ion Implantation and Annealing for an Efficient N-Doping of TiO2 Nanotubes , 2006 .

[52]  H. Minoura,et al.  Designing a TiO2 Nano‐Honeycomb Structure Using Photoelectrochemical Etching , 1999 .

[53]  M. Misra,et al.  Synthesis of self-organized mixed oxide nanotubes by sonoelectrochemical anodization of Ti–8Mn alloy , 2007 .

[54]  Patrik Schmuki,et al.  TiO2 nanotubes: synthesis and applications. , 2011, Angewandte Chemie.

[55]  Karumbaiah N. Chappanda,et al.  Growth and characterization of TiO2 nanotubes from sputtered Ti film on Si substrate , 2012, Nanoscale Research Letters.

[56]  M. Misra,et al.  Water Photooxidation by TiSi2-TiO2 Nanotubes , 2011 .

[57]  Mano Misra,et al.  Vertically oriented TiO2 nanotube arrays grown on Ti meshes for flexible dye-sensitized solar cells , 2009 .

[58]  R. Wilson,et al.  Aging Effects in Single Crystal Reduced Rutile Anodes , 1976 .

[59]  Shiwei Lin,et al.  Photocatalytic degradation of methyl orange using a TiO2/Ti mesh electrode with 3D nanotube arrays. , 2012, ACS applied materials & interfaces.