Improved thermoelectric properties of multi-walled carbon nanotubes/Ag2Se via controlling the composite ratio

Abstract

The development of high-efficiency thermoelectric materials is extremely important for energy harvesting. In this study, novel MWCNTs/Ag₂Se (MCAS) composites were successfully fabricated via a typical one-pot hydrothermal method and their thermoelectric properties were discussed in the temperature range from 300–420 K. SEM images revealed that the microparticle diameter of Ag₂Se in MCAS was about 10 times smaller than that of pure Ag₂Se, which contributed to close contact and a synergistic effect at the MCAS interface. Thermoelectric measurements indicated that 1%MCAS obtained the optimal thermoelectric figure of merit (ZT) value, and this was ascribed to the outstanding electrical conductivity of the MWCNTs and the lowered thermal conductivity of 1%MCAS. The electrical conductivity of 1%MCAS was 3.0 times higher than that of Ag₂Se, and the lattice thermal conductivity decreased by 55.3% at 300 K. This study provides a new strategy for designing Ag₂Se-based thermoelectric materials and promoting thermoelectric performance.