Mass Production of Pt Single-Atom-Decorated Bismuth Sulfide for n-Type Environmentally Friendly Thermoelectrics

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 Pt 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.