Vanadium oxide sensing layer grown on carbon nanotubes by a new atomic layer deposition process

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Carbon nanotubes (CNTs) offer high surface area but require functionalization for specific applications.
• Vanadium oxide (VOx) is a promising material for gas sensing due to its redox properties.
• Achieving uniform and conformal coatings on CNTs is challenging.

Purpose of the Study:

• To develop a new atomic layer deposition (ALD) process for homogeneous vanadium oxide coating on carbon nanotubes.
• To produce high surface area hybrid materials with controlled thickness and unprecedented quality.
• To investigate the performance of these ALD-coated CNTs in gas-sensing devices.

Main Methods:

• Utilized a novel atomic layer deposition (ALD) process for vanadium oxide deposition.
• Applied the ALD process to coat both inner and outer surfaces of carbon nanotubes.
• Fabricated gas-sensing devices using the ALD-coated CNTs as the active component.

Main Results:

• Achieved highly conformal vanadium oxide films of controllable thickness on CNTs.
• Produced high surface area hybrid materials with superior uniformity.
• Observed electric responses in gas-sensing devices directly correlated with the p-n heterojunction structure between CNTs and vanadium oxide.

Conclusions:

• The new ALD process enables high-quality, homogeneous vanadium oxide coating on CNTs.
• The resulting hybrid materials are effective active components in gas-sensing devices.
• The observed gas-sensing performance is attributed to the unique p-n heterojunction formed at the interface.