Login | Signup now       

Guest

 Click to see how  

HOME | VIDEOS | DOCUMENTS | COLLECTIONS | UPLOAD | BROADCAST | MY ACCOUNT | FEEDBACK | ABOUT

 

Share  Title: Hydrogen sensors based on titania nano-tubes

 

 
Abstract

 Download Papers  Read full document

 
 
 
iConnect (Beta)   |   Sponsor  |   Comment   |    Report    Like    
 
 

This article is a literature survey on the fabrication of novel H2 sensors based on titania nano-tubes prepared using anodization and annealed in an oxygen atmosphere. The as prepared nano-tubes are amorphous but they crystallize on annealing at elevated temperatures and are structurally stable (which is a requirement of any sensor) to at least 600 °C.Titania nano-tubes are grown from titanium foil (≈99.5% pure) of thickness 0.25 mm. The anodization is performed in an electrolyte medium of 0.5% hydrofluoric acid in water, using a platinum foil cathode. A well defined nano-tube architecture results, with nano-tube length of 400 nm in approximately 20 minutes.Measurement of H2 concentration is based on the increase in conductivity of the nano-tube surface in a hydrogen ambient as compared to its original conductivity, and this is quantified by ’sensitivity’ ratio, S = (R0 – Rgas)/Rgas (where R0 is the electrical resistance of the sensor before passing the gas and Rgas that after passing gas and reaching the saturation value). The sensor shows significant hydrogen sensitivity, with a three order of magnitude change in resistance as compared to its original resistance. The major process behind the interaction between the nano-tubes and hydrogen is the chemisorption of the dissociated hydrogen on the titania surface.These sensors find application in industrial process control, combustion control, gas leak detection from hydrogen-powered cars and fueling stations and in medical applications with hydrogen indicating certain types of bacterial infection. These nano-tube sensors can monitor hydrogen levels from parts per billion to about 1000 ppm.These sensors have a special ability to ‘clean’ themselves up. The photocatalytic properties of titania nano-tubes are so large (a factor of 100 times greater than any other form of titania) that sensor contaminants are efficiently removed with exposure to ultraviolet light, so that the sensors effectively recover or retain their original hydrogen sensitivity in real world application. These sensors have also been shown to be completely reversible, with respect to their original conductivity, which means that when the hydrogen gas exposure is cut-off, they regain their original resistance without any hysteresis.

 
 
Download Papers  Read full document
 
 
 
Most Viewed This Month
Supersonic Nozzle design by Method of Characteristics
A report discussing critical factors affecting Project performance
JPEG Progressive mode vs Sequential mode
Rayleigh criteria and Combustion Instability
Business Plan for Online Money Transfer
Adaptive Equalization Techniques using Least Mean Square (LMS) algorithm
Girlkultur – Mass Culture in Weimar Germany
Adaptive Equalization Techniques using Recursive Least Square (RLS) algorithm
Combustion Instability in Liquid Rocket Engines
A Technical Essay on the Gyroplane
Laminar Separation Bubble
Experimental Study of Compressible Pipe Flow with Friction and Heat Addition
NOTAR Helicopter
The Role of Density Gradient in Liquid Rocket Engine Combustion Instability
Quasi-one-dimensional models for glassy dynamics
 
Related Documents
Hydrogen sensors based on titania nano-tubes
Fiber-Optic based Dynamic Pressure sensor for Combustion
The Behaviour of Air (Nitrogen) inside Carbon Nanotubes
The Combustion of Aluminum in Solid Rocket Propellants
Software issues encountered while modeling continuous phenomena
Temperature measurements during Reentry
Evaluation of phase and magnitude based features for speaker identification
Evaluation of Phase & Magnitude based Features for Speaker Identification
Evaluation of Feature Recombination Techniques for Speaker Identification
The Role of Density Gradient in Liquid Rocket Engine Combustion Instability
Computational Support for the Collaborative Design, Routing, and Manipulation of Cable Harnesses
Decline of the Tip-Jet
The Thomas B. Fordham Institute, Chester Finn, and Liberal Education in America
Complex Classification Using Advanced Machine Learning Techniques
A Machine Learning approach to localization in Wireless Sensor Networks
 
Member Documents
Hydrogen sensors based on titania nano-tubes
Plasma Wind Tunnels
Temperature measurements during Reentry
Coefficient of Thermal Expansion and Thermal Shock Parameter
Sustainable Energy Production and Utilization In Semi-rural Arizona
 

Keywords

Hydrogen  sensors  titania  nano  tubes  carbon  
 
 
 About This Document
 
 Subject Mechanical Engineering
 Category White Paper
 Views 3158
 Downloads 243
 Added 12-08-09
 Contributor   sidpatel
 Add to Favourites
 Report Abuse
 
 Related Videos
 See More

 RunTime  00:04:58
 Uploaded  25-11-07
 Views  3224
   
 Sound, Vision & Nanoscien...

 RunTime  00:03:42
 Uploaded  26-12-07
 Views  3414
   
 Hydrogen Fuel Cell

 RunTime  moderate
 Uploaded  02-09-11
 Views  1778
   
 Improving the safety of a...

 RunTime  00:07:47
 Uploaded  28-11-07
 Views  3205
   
 Micro and nanotechnologie...

 RunTime  01:14:54
 Uploaded  28-11-07
 Views  3266
   
 Chemistry 3B - Lecture 03...

 RunTime  00:00:02
 Uploaded  30-10-07
 Views  2985
   
 Dna Molecular Biology Vis...

 RunTime  00:09:12
 Uploaded  18-11-07
 Views  3252
   
 Solid Oxide Fuel Cells

 RunTime  00:03:20
 Uploaded  28-12-07
 Views  3075
   
 Video Journey Into Nanote...

 RunTime  00:02:39
 Uploaded  15-01-10
 Views  3417
   
 Kennedy Space Center STS ...

 RunTime  00:01:36
 Uploaded  26-12-07
 Views  2832
   
 Inside - CNSE Kathleen Du...

 RunTime  00:03:20
 Uploaded  28-11-07
 Views  3099
   
 Video Journey Into Nanote...

 RunTime  00:03:32
 Uploaded  27-12-07
 Views  2836
   
 Carbon Nanotubes

 RunTime  00:06:17
 Uploaded  27-12-07
 Views  9261
   
 Walter Lewin Makes a Batt...

 RunTime  00:09:07
 Uploaded  14-02-09
 Views  3423
   
 DAC Lab - Data Acquisitio...

 RunTime  moderate
 Uploaded  15-02-15
 Views  1008
   
 Superhydrophobic Surface ...

 RunTime  00:00:02
 Uploaded  06-11-07
 Views  3691
   
 The Hubble Deep Field: Th...

 RunTime  00:05:11
 Uploaded  13-01-10
 Views  3629
   
 Aeroelastic Tests of an E...

 RunTime  00:10:32
 Uploaded  26-08-09
 Views  3364
   
 The Overtone Series

 

 

Comments | Queries | Clarifications