Enhanced thermoelectric performance in Cu3SbSe4-based materials through incorporating 2D MXenes

Ternary copper-based Cu 3 SbSe 4 compound has emerged as a promising thermoelectric material. However, its practical application is limited by relatively low thermoelectric performance, primarily due to inferior electrical properties. In this work, the Cu 3 SbSe 4 -based composites with incorporated 2D MXenes ( i.e. , Ti 3 C 2 T x ) were synthesized by combining mechanical alloying with spark plasma sintering technique. The introduction of 2D Ti 3 C 2 T x nanosheets significantly enhanced the Seebeck coefficient, which is ascribed to the energy-dependent carrier scattering. Resultantly, an optimized PF  ~ 1.1 mWm −1  K −2 can be realized in the bulk composite with x  = 1.5. All composite samples exhibited low thermal conductivity in high temperature, attributed to enhanced interfacial phonon scattering. As a result, the best ZT value of 0.59 at 623 K is obtained for the bulk Cu 3 Sb 0.98 Sn 0.02 Se 4 /1.5 vol % Ti 3 C 2 T x composite, which increases by 31% compared with that of the matrix. This study demonstrates that incorporation of 2D MXenes into ternary copper-based compounds is an effective strategy to enhance their TE performance.