Achieving Superior Thermoelectric Performance in Methoxy-Functionalized MXenes: The Role of Organic Functionalization

Area of Science:

• Materials Science
• Solid State Physics
• Energy Conversion

Background:

• Thermoelectric technology offers a sustainable energy solution by converting heat to electricity.
• MXenes are a promising class of 2D materials for various applications, including thermoelectrics.
• Organic functionalization of MXenes is an emerging strategy to tune their properties.

Purpose of the Study:

• To investigate the stability, electronic structure, and thermoelectric properties of methoxy-functionalized M2C(OMe)2 MXenes.
• To explore the potential of these functionalized MXenes as high-performance thermoelectric materials.
• To establish an effective organic functionalization strategy for designing advanced MXene-based thermoelectrics.

Main Methods:

• First-principles calculations were employed to study material properties.
• Semiclassical Boltzmann transport theory was used to evaluate thermoelectric performance.
• Systematic investigation of various transition metals (M = Sc, Ti, V, Cr, Y, Zr, Nb, Mo, Hf, Ta, W) in M2C(OMe)2 structures.

Main Results:

• Methoxy-functionalized M2C(OMe)2 MXenes, except for M = Cr, Mo, W, are predicted to be synthesizable.
• Sc2C(OMe)2 and Y2C(OMe)2 exhibit exceptionally high peak ZT values (15.02 and 12.11, respectively) at 900 K under n-type doping.
• These materials achieve a remarkable thermoelectric conversion efficiency of 53% at a temperature difference of 600 K.

Conclusions:

• The methoxy group's electronic nature and specific band structure features contribute to superior thermoelectric performance.
• The study presents a viable organic functionalization approach for developing high-performance MXene thermoelectrics.
• These findings provide valuable insights for the design of next-generation thermoelectric materials for industrial applications.