Enhancing thermoelectric properties of n-type Bi2Te2.55Se0.45 through the incorporation of MXene nanosheets

This paper investigates the impact of incorporating two-dimensional MXene (specifically Ti 3 C 2 ) into n-type Bi 2 Te 2.55 Se 0.45 alloys using ball-milling and hot-pressing techniques. The thermoelectric properties of various MXene contents (0.01, 0.05, 0.5, 1, 2, 3, and 4 Wt%) in the nanocomposite were explored. The synthesized 2 wt% MXene-Bi 2 Te 2.55 Se 0.45 nanocomposite exhibited an average grain size of 74 ± 25 nm. The X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) analysis have confirmed the insolubility of MXene within the Bi 2 Te 2.55 Se 0.45 matrix, establishing its presence as a nanofiller. TEM results further revealed a homogenous dispersion of MXene as multilayer nanoparticles, which are 50 to 100 nm in size. Measuring the thermoelectric properties of the prepared nanocomposites showed that the incorporation of MXene improved the charge transport properties–but only at low concentrations (0.01 wt%). The calculated ZT profile of this sample reached 0.84 at 150 °C, resulting in 11 % improvements compared to the pristine Bi 2 Te 2.55 Se 0.45 pellet at the same temperature. • Bismuth telluride is a key near-room temperature thermoelectric material, but its low efficiency limits applications. • The p-type bismuth telluride showed improved ZT values; however, the ZT values of the n-type remain dreadfully low. • Nanostructuring and nanocompositing can significantly enhance the thermoelectric properties of these materials. • This manuscript explores the incorporation of MXene as a nanofiller in the n-type Bi 2 Te 2.55 Se 0.45 material at varying concentrations. • Adding 0.01 wt% MXene to the Bi 2 Te 2.55 Se 0.45 nanocomposite resulted in an 11 % improvement in ZT compared to the pristine sample.