TiO₂/(K,Na)NbO₃ Nanocomposite for Boosting Humidity-Sensing Performances

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Humidity sensors are crucial for environmental monitoring and industrial processes.
• Developing materials with high sensitivity and rapid response is essential for advanced humidity sensing.

Purpose of the Study:

• To synthesize and characterize TiO2, (K0.5Na0.5)NbO3, and their nanocomposite.
• To fabricate and evaluate impedance-type humidity sensors based on these materials.
• To investigate the synergistic effects in the TiO2/(K0.5Na0.5)NbO3 nanocomposite for enhanced humidity sensing.

Main Methods:

• Hydrothermal synthesis for nanomaterial preparation.
• Fabrication of impedance-type humidity sensors.
• Performance testing across a wide relative humidity range (12-94%).

Main Results:

• The TiO2/(K0.5Na0.5)NbO3 sensor exhibited an impedance change of 5 orders of magnitude.
• An ultrahigh sensing response (Sf = 166,470 at 100 Hz) was recorded.
• The nanocomposite sensor showed fast response/recovery times (25/38 s), low hysteresis (<5%), and excellent stability.

Conclusions:

• The TiO2/(K0.5Na0.5)NbO3 heterojunction exhibits a synergistic effect, significantly boosting humidity-sensing properties.
• Constructing nanocomposites is an effective strategy for improving humidity sensor performance.
• This research presents a facile method for developing high-performance humidity sensors.