An ultra-sensitive NH₃ gas sensor enabled by an ion-in-conjugated polycroconaine/Ti₃C₂T core-shell composite

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• MXenes offer excellent conductivity for sensing but lack stability.
• Functional polymers can enhance MXene stability and sensing performance.

Purpose of the Study:

• To develop a stable MXene-polymer composite for ammonia (NH3) detection.
• To improve the sensitivity and stability of MXene-based gas sensors.

Main Methods:

• Fabrication of a Ti3C2Tx@croconaine (PDAC) core-shell composite via in situ polymerization.
• Gas sensing performance evaluation for NH3 detection.
• Density Functional Theory (DFT) calculations for gas adsorption analysis.

Main Results:

• The Ti3C2Tx@PDAC composite sensor exhibited enhanced sensitivity (2.8% ppm-1) and a low limit of detection (50 ppb) for NH3.
• The PDAC shell improved sensor stability, with reliable operation for over 40 days.
• A flexible paper-based sensor demonstrated robust performance under mechanical deformation.

Conclusions:

• The Ti3C2Tx@PDAC composite offers a promising strategy for developing highly sensitive and stable gas sensors.
• The study highlights a novel mechanism for enhancing MXene-based sensor performance through polymer incorporation.
• This work presents a feasible methodology for creating advanced MXene-polymer composites for chemical sensing applications.