Hydrothermal Synthesis of Stable 1T-WS2 and Single-Walled Carbon Nanotube Hybrid Flexible Thin Films with Enhanced Thermoelectric Performance

Abstract

Two-dimensional stable metallic 1T phase of transitional metal dichalcogenide (TMDC) nanosheets have attracted attention as promising, flexible, thermoelectric (TE) materials. Here, 1T phase tungsten disulfide/single walled carbon nanotube (1T-WS2/SWCNT) hybrid composites with excellent TE performance are prepared using a hydrothermal method, and they are demonstrated to have a unique 3D architecture interweaving between the SWCNT bundles and WS2 nanosheets. Flexible thin films are fabricated using a facile vacuum filtration technique. Under the optimal conditions, the maximum electrical conductivity reached 318 S cm?1 with a Seebeck coefficient of 43.2 ��V K?1 at room temperature, leading to an impressive power factor of 61.70 ��W m?1 K?2. The introduction of SWCNTs into 1T-WS2 may significantly improve the TE performance by simultaneously enhancing the electrical conductivity and Seebeck coefficient due to the synergistic effect of the conductive paths and interfacial interaction. Furthermore, the TE properties were stable for at least half one year in the ambient environment because of the high stability of 1T-WS2 synthesized through hydrothermal method. This novel strategy demonstrates an effective way to optimize the TE performance of metallic 1T phase TMDCs and a variety of TMDC-based hybrid composites have great potential for future TE applications. (c) 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei