Interfacial charge transfer and thermoelectric optimization in MoS2 enabled by secondary-doped PANI intercalation

Transition metal chalcogenides have attracted great attention due to their excellent thermoelectric properties. Among them, MoS 2 submicrospheres assembled from layered nanosheets have emerged as particularly promising candidates for thermoelectric applications. However, the intrinsiclly low electrical conductivity of MoS 2 hinders the further enhancement of its performance. In this work, MoS 2 /polyaniline (PANI) nanocomposites were synthesized by a hydrothermal method. The thermoelectric properties were systematically tuned by controlling the mass fraction of secondary-doped PANI, and the role of interfacial effects on carrier transport was analyzed. X-ray diffraction confirmed the intercalation of PANI into the MoS 2 layers, while Fourier transform infrared spectroscopy verified the formation of PANI–H 2 SO 4 –DBSA. Composition-dependent studies revealed that PANI intercalation effectively modulates the band structure of MoS 2 , leading to a pronounced band shift. Thermoelectric measurements showed that the electrical conductivity of the composites increased by about five times compared with pure MoS 2 , while maintaining p-type conduction. The power factor was enhanced by nearly twelve times. This study demonstrates a synergistic optimization of electrical conductivity and Seebeck coefficient through interfacial engineering, providing a new strategy for developing high-performance thermoelectric materials for medium- and low-temperature waste heat recovery. • Secondary-doping–assisted PANI intercalation achieves genuine gallery insertion in MoS 2 . • A band-alignment/polaron framework explains charge redistribution and energy-selective transport with lower Ea. • p-Type thermoelectric performance: conductivity increases, Seebeck retained, PF ≈ 8.4 μW·m −1 ·K −2 at 420 K. • Composition/temperature operating window identified for optimizing interfacial transport.