Single-atom materials are widely explored in catalysis, batteries, sensors, etc. However, limited by mass production and centimeter-scale assembly, they are rarely studied in thermoelectrics. Herein, we demonstrate a solvothermal synthesis assisted by a syringe-pump method to yield Bi2S3-supported Pt single-atom materials (Bi2S3-Pt1) at a 10 g scale. Different from Ptn clusters, Pt1 single atoms can increase carrier concentration at a high doping efficiency and provide a unique atomic environment to enhance carrier mobility, and an enlarged effective mass leads to an enhanced Seebeck coefficient. As a result, a high power factor (348 μW m-1 K-2) is achieved at 823 K. Benefiting from the scattering of phonons by Pt1 atomic sites, a minimum thermal conductivity of 0.37 W m-1 K-1 is achieved. Consequently, the Bi2S3-0.5 wt % Pt1 realizes a record-high zT of ∼0.75 at 823 K, being among the best in the state-of-the-art n-type environmentally friendly metal sulfides. The enhancement of the carrier mobility and suppression of the thermal conduction by the unique Pt1 single atoms will inspire various fields, as exemplified by electronic devices and thermal management.
Keywords: DFT; Metal chalcogenide; Single atoms; Thermoelectrics.