In this paper, Bi₂Te₃ nanosheets were firstly synthesized by solvothermal method, and then Ti₃C₂T_x (indicating O, F, OH, etc.) was introduced into bismuth telluride nanosheets with good thermoelectric properties as the second phase by the composite method of "ultrasonic dispersion-flash freeze-freeze-drying" combined with discharge plasma sintering technique, and the Bi₂Te₃/Ti₃C₂T_x nanocomposites were successfully prepared. The effects of different contents of Ti₃C₂T_x on the thermoelectric properties of Bi₂Te₃/Ti₃C₂T_x nanocomposites were also investigated. The samples were characterized and performance tested using scanning electron microscope, transmission electron microscope, thermoelectric test system, and laser thermal conductivity meter. The results show that the introduction of titanium carbide into the bismuth telluride nanomatrix increases the carrier concentration of bismuth telluride, leading to an increase in conductivity and a decrease in Seebeck coefficient, but the energy barrier scattering at the composite interface avoids a significant decrease in Seebeck coefficient; the nanocrystalline boundary between titanium carbide and bismuth telluride increases phonon scattering and interfacial thermal resistance and decreases thermal conductivity. The 1 vol% bismuth Bi₂Te₃/Ti₃C₂T_x nanocomposites showed a 25% increase in thermoelectric figure of merit compared to the bismuth Bi₂Te₃ nanomatrix. 1 vol% Bi₂Te₃/Ti₃C₂T_x nanocomposites had the highest ZT value of 0.908 at 432 K and the average ZT value of 0.87 in the range of 376-511 K.
 

Bi2Te3/Ti3C2Tx nanocomposites; Solvothermal method; ZT value; Thermoelectric performance.