Highly NH₃ Sensitive and Selective Ti₃C₂O₂-Based Gas Sensors: A Density Functional Theory-NEGF Study

Area of Science:

• Materials Science
• Nanotechnology
• Environmental Science

Background:

• Early-stage ammonia (NH3) detection is crucial for health and agriculture.
• Conventional sensors struggle with low power consumption and high selectivity.
• MXenes offer promising properties for gas sensing due to abundant surface sites.

Purpose of the Study:

• To investigate the sensing performance of Ti3C2O2 for ammonia detection.
• To understand the interaction mechanisms between NH3 and Ti3C2O2 using theoretical methods.
• To evaluate the practical application of Ti3C2O2 in a gas sensor device.

Main Methods:

• Density functional theory (DFT) calculations.
• Non-equilibrium Green's function (NEGF) simulations.
• Fabrication and characterization of a two-electrode Ti3C2O2-based gas sensor.

Main Results:

• NH3 selectively chemisorbs onto the Ti3C2O2 nanosheet.
• The Ti3C2O2-based sensor demonstrates extremely high sensitivity to NH3.
• External electric fields effectively tune adsorption energy and charge transfer.

Conclusions:

• Ti3C2O2 shows significant potential as a highly selective and sensitive ammonia sensor with low energy consumption.
• The material's properties can be modulated by external electric fields, enhancing its versatility.
• This research paves the way for developing advanced NH3 gas sensing technologies.