Fabrication and investigation of gas sensing properties of Nb-doped TiO2 nanotubular arrays

Synthesis of Nb-containing titania nanotubular arrays at room temperature by electrochemical anodization is reported. Crystallization of pure and Nb-doped TiO(2) nanotubes was carried out by post-growth annealing at 400°C. The morphology of the tubes obtained was characterized by scanning electron microscopy (SEM). Crystal structure and composition of tubes were investigated by glancing incidence x-ray diffraction (GIXRD) and total reflection x-ray fluorescence (TXRF). For the first time gas sensing characteristics of Nb-doped TiO(2) nanotubes were investigated and compared to those of undoped nanotubes. The functional properties of nanotubular arrays towards CO, H(2), NO(2), ethanol and acetone were tested in a wide range of operating temperature. The introduction of Nb largely improves conductivity and enhances gas sensing performances of TiO(2) nanotubes.

[1]  Christian Elsässer,et al.  Density functional theory study of dopants in polycrystalline TiO 2 , 2011 .

[2]  Tetsuya Kida,et al.  Gas sensing characteristics and porosity control of nanostructured films composed of TiO2 nanotubes , 2009 .

[3]  Matteo Ferroni,et al.  Synthesis and characterization of semiconducting nanowires for gas sensing , 2007 .

[4]  Giorgio Sberveglieri,et al.  Flexible dye sensitized solar cells using TiO2 nanotubes , 2011 .

[5]  Craig A. Grimes,et al.  Unprecedented ultra-high hydrogen gas sensitivity in undoped titania nanotubes , 2006 .

[6]  Zafer Ziya Öztürk,et al.  Synthesis of highly-ordered TiO2 nanotubes for a hydrogen sensor , 2010 .

[7]  M. Pardo,et al.  Metal Oxide Nanowire and Thin-Film-Based Gas Sensors for Chemical Warfare Simulants Detection , 2008, IEEE Sensors Journal.

[8]  A. J. Frank,et al.  Microstructure and pseudocapacitive properties of electrodes constructed of oriented NiO-TiO2 nanotube arrays. , 2010, Nano letters.

[9]  Matteo Ferroni,et al.  Metal oxide nanowires: Preparation and application in gas sensing , 2009 .

[10]  G. Sberveglieri,et al.  Columnar CeO2 nanostructures for sensor application , 2007 .

[11]  Alessandro Martucci,et al.  Gold Nanoparticle‐Doped TiO2 Semiconductor Thin Films: Gas Sensing Properties , 2008 .

[12]  Craig A. Grimes,et al.  A review on highly ordered, vertically oriented TiO2 nanotube arrays: Fabrication, material properties, and solar energy applications , 2006 .

[13]  L. Sangaletti,et al.  Correlation between crystallite sizes and microstrains in TiO2 nanopowders , 1999 .

[14]  Tetsuya Kida,et al.  Detection of organic gases using TiO2 nanotube-based gas sensors , 2009 .

[15]  Giorgio Sberveglieri,et al.  TiO2 nanotubular and nanoporous arrays by electrochemical anodization on different substrates , 2011 .

[16]  R. Freer,et al.  NO2 sensitivity of a heterojunction sensor based on WO3 and doped SnO2 , 2003 .

[17]  Kengo Shimanoe,et al.  Theory of gas-diffusion controlled sensitivity for thin film semiconductor gas sensor , 2001 .

[18]  Kengo Shimanoe,et al.  Cr-doped TiO2 gas sensor for exhaust NO2 monitoring , 2003 .

[19]  Carles Cané,et al.  Micro-machined WO3-based sensors selective to oxidizing gases , 2008 .

[20]  Maolin Zhang,et al.  Improvement and mechanism for the fast response of a Pt/TiO2 gas sensor , 2010 .

[21]  Giorgio Sberveglieri,et al.  Cr-inserted TiO2 thin films for chemical gas sensors , 2007 .

[22]  Baikun Li,et al.  Ammonia Gas Sensor Using Polypyrrole‐Coated TiO2/ZnO Nanofibers , 2009 .

[23]  Il-Doo Kim,et al.  Ultrasensitive and Highly Selective Gas Sensors Based on Electrospun SnO2 Nanofibers Modified by Pd Loading , 2010 .

[24]  Matteo Ferroni,et al.  Single crystal ZnO nanowires as optical and conductometric chemical sensor , 2007 .

[25]  H. Imai,et al.  Crystal phase control for titanium dioxide films by direct deposition in aqueous solutions , 2002 .

[26]  G. Sberveglieri,et al.  Controlled Growth and sensing properties of In2O3 nanowires , 2007 .

[27]  Dmitri O. Klenov,et al.  Enhanced gas sensing by individual SnO2 nanowires and nanobelts functionalized with Pd catalyst particles. , 2005, Nano letters.

[28]  Matteo Ferroni,et al.  Quasi-one dimensional metal oxide semiconductors: Preparation, characterization and application as chemical sensors , 2009 .

[29]  Craig A. Grimes,et al.  Synthesis and application of highly ordered arrays of TiO2 nanotubes , 2007 .

[30]  Giorgio Sberveglieri,et al.  Solar Cells: Vertically Aligned TiO2 Nanotubes on Plastic Substrates for Flexible Solar Cells (Small 17/2011) , 2011 .

[31]  Yasushi Sato,et al.  Transparent conductive Nb-doped TiO2 films deposited by direct-current magnetron sputtering using a TiO2-x target , 2008 .

[32]  Craig A. Grimes,et al.  A Sentinel Sensor Network for Hydrogen Sensing , 2003 .

[33]  L. Sangaletti,et al.  Niobium-titanium oxide powders obtained by laser-induced synthesis: Microstructure and structure evolution from diffraction data , 1998 .

[34]  Prabir K. Dutta,et al.  Oxidation chemistry and electrical activity of Pt on titania: development of a novel zeolite-filter hydrocarbon sensor , 2004 .

[35]  Dong Xiang,et al.  Metal Oxide Gas Sensors: Sensitivity and Influencing Factors , 2010, Sensors.