Investigation of thermoelectric properties of flexible Ti3C2Tx MXene membranes

Abstract

Two-dimensional MXenes have recently emerged as potential candidates for their excellent electrical and mechanical properties. We report the controlled modulation of thermoelectric properties in Ti₃C₂T_x flexible membranes via vacuum annealing. The as-prepared flexible membrane shows the highest electrical conductivity (∼5000 S m⁻¹ at 373 K) and slightly estimated ZT value of 4.4 × 10⁻³ at 420 K due to preserved surface terminations and intercalated water contents. Notably, annealing at 300 °C enhances the Seebeck coefficient (∼450 µV K⁻¹) and optimizes the power factor (∼105 µW m⁻¹ K⁻² at 450 K), whereas high temperature annealing (400 °C) significantly reduced thermoelectric performance due to excessive oxidation and degradation of the membrane. This work highlights that the tunability of MXene films through controlled annealing and surface functional group modification can significantly enhance the performance of thermoelectric materials for room- to mid-temperature range applications. The investigation of MXenes' thermoelectric properties opens new avenues for their use in flexible electronics and wearable devices.