Vapor phase polymerization of Ag QD-embedded PEDOT film with enhanced thermoelectric and antibacterial properties

Nonferric oxidant precursors have the unique advantage of directly polymerizing poly(3,4-ethylenedioxythiophene) (PEDOT)-inorganic composites. However, due to limited solubility and unmatched oxidation potentials, most oxidants only produce powders or porous materials. To obtain high-quality films with improved homogeneity and controllable particle sizes, the oxidants should be adaptable to high-standard PEDOT film fabrication techniques such as vapor phase polymerization (VPP). In this work, we discovered for the first time a nonferric metal salt suitable for the VPP process. With the addition of an Fe(III) salt to stabilize the reaction and adjust the oxidant ratio, micron-thick antibacterial S-PEDOT-Ag quantum dot (QD) composite films with tunable Ag wt% can be synthesized in one facile step. With a low Ag loading of ~0.2 wt%, the film exhibited an optimized power factor of 63.1 μW/mK2, which is among the highest values thus far reported for PEDOT-metal composites. Increase of the Ag(I) concentration in the precursor to a certain level may lead to minor decomposition of the polymer followed by the formation of Ag2S particles. We synthesized small-sized ion doped PEDOT-Ag quantum dot (S-PEDOT-Ag QD) composite film via one-step vapor phase polymerization (VPP) using a novel Ag(I) salt precursor. The films exhibit enhanced thermoelectric performance and good antibacterial activity at low Ag loadings. This facile approach provides new route to synthesize high performance conducting polymer–inorganic composite.