Defect Engineering for Flexible n-Type Mo₂TiC₂T o-MXene Thermoelectric Efficiency Enhancement

Area of Science:

• Materials Science
• Energy Harvesting
• Nanotechnology

Background:

• Wearable electronics require efficient portable power.
• Thermoelectric materials convert heat to electricity, offering sustainable energy.
• Developing flexible thermoelectric materials for body heat harvesting is challenging.

Purpose of the Study:

• To develop flexible, high-performance thermoelectric materials for body heat harvesting.
• To investigate the effects of surface oxygen defects and microstructure optimization in MXene materials.
• To create a wearable thermoelectric generator using enhanced MXene films.

Main Methods:

• Synthesized flexible, ammoniated N-Mo2TiC2Tx MXene materials.
• Employed high-temperature ammoniation to tune surface properties and microstructure.
• Conducted theoretical and experimental analyses to evaluate thermoelectric properties.
• Fabricated and tested a wearable thermoelectric generator.

Main Results:

• High-temperature ammoniation reduced oxygen defects and interlayer spacing, boosting electrical conductivity.
• Nitrogen incorporation enhanced the Seebeck coefficient.
• Achieved a power factor of 7.99 μW m-2 K-2, a 1.2-fold increase, with excellent flexibility.
• Demonstrated a wearable thermoelectric generator producing 1.4 mV with a 12 K temperature gradient.

Conclusions:

• Synergistic tuning of surface defects and microstructure in N-Mo2TiC2Tx MXene enhances thermoelectric performance.
• The developed flexible MXene films are suitable for harvesting low-grade thermal energy.
• This work presents a new strategy for next-generation wearable and industrial energy applications.