Chemiresistive Gas Sensors Based on Ni₃(HITP)₂/Ti₃C₂ Heterojunctions for ppb-Level NH₃ Detection at Room Temperature

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Growing industrial demand for efficient ammonia (NH3) monitoring.
• Need for room-temperature gas sensors with high performance.

Purpose of the Study:

• To develop a novel Ni3(HITP)2/Ti3C2 hierarchical heterojunction material.
• To fabricate a room-temperature gas sensor using MEMS technology for NH3 detection.

Main Methods:

• Fabrication of Ni3(HITP)2/Ti3C2 heterojunction.
• Gas sensor fabrication using MEMS technology.
• Material characterization (SEM, TEM, XRD, XPS, BET) and DFT calculations.

Main Results:

• The composite material exhibited high sensitivity (0.1 ppm) and fast response (9 s) to NH3.
• Excellent selectivity toward NH3 at room temperature was achieved.
• Charge transfer and built-in electric field at the interface enhanced gas adsorption and electron transport.

Conclusions:

• The Ni3(HITP)2/Ti3C2 heterojunction offers a promising strategy for low-power, high-performance NH3 gas sensors.
• The developed sensor demonstrates robust long-term stability and repeatability.
• This work paves the way for a new generation of advanced gas sensing technologies.