Ni-doped TiO2 nanotubes for wide-range hydrogen sensing

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Doping titanium dioxide (TiO2) nanotubes enhances their physical and chemical properties for advanced applications.
• Developing efficient hydrogen sensors is crucial for safety and energy applications.

Purpose of the Study:

• To fabricate Ni-doped TiO2 nanotube arrays and investigate their hydrogen sensing performance.
• To explore the electronic structure and sensing mechanisms of Ni-doped TiO2 using experimental and computational methods.

Main Methods:

• Fabrication of Ni-doped TiO2 nanotube arrays via electrochemical anodization and annealing.
• Investigation of hydrogen sensing performance across a range of concentrations (50 ppm to 2% H2) and temperatures (25°C to 200°C).
• Utilizing first-principles calculations to analyze electronic structure and hydrogen interaction.

Main Results:

• The Ni-doped TiO2 nanotube sensor exhibited high sensitivity to a wide range of hydrogen concentrations.
• Temperature-dependent sensing characteristics were observed between 25°C and 200°C.
• Computational analysis revealed Ni substitution induces conductivity type inversion and bandgap reduction, correlating resistance changes with the bandgap and impurity levels.

Conclusions:

• Ni-doped TiO2 nanotubes offer a promising platform for sensitive and reliable hydrogen detection.
• The electronic structure modifications induced by Ni doping are key to the enhanced sensing properties.
• Understanding the interplay between doping, electronic structure, and hydrogen absorption is vital for sensor optimization.