Silica-modified few-layered MoS2 for SWCNT-based thermoelectric materials

The design and construction of carbon nanotubes (CNT)-based thermoelectric materials are benefit for developing self-powered wearable devices. Molybdenum disulfide (MoS2) with few layers has been pursued to enhance the thermoelectric properties of CNT due to its high carrier mobility and energy filtering effect. In this work, sulfhydryl silica nanoparticles were firstly synthesized as a concomitant sulfur source, and the SiO2@MoS2 with few layers was prepared by hydrothermal method. By light doping SiO2@MoS2 with few layers, the carrier mobility of the SiO2@MoS2/SWCNT is further improved due to the enhanced interfacial interaction between MoS2 and SWCNTs, and the Seebeck coefficient was improved obviously without significant decrease in electrical conductivity, thus improving the power factor (PF) of the SWCNTs. Here, the maximum Seebeck coefficient, electrical conductivity, and PF values for SiO2@MoS2/SWCNT obtained at room temperature were 39.2 ± 0.2 μV K−1, 1646.4 ± 117.2 S cm−1 and 253.2 ± 21.1 μW m−1 K−2, respectively. In addition, the PF was further enhanced to 303.3 μW m−1 K−2 at 435 K. Moreover, a thermoelectric device was assembled by connecting SiO2@MoS2/SWCNT films and copper sheets in series, which exhibited an open circuit voltage of 11.2 mV and an output power of 1.1 μW under a temperature gradient of 50 K. Therefore, this work opens a novel avenue for fabricating CNT-based thermoelectric materials with high performance, which has potential application in converting heat energy into electrical power at middle-low temperature.