Template-Free Fabrication and Thermoelectric Properties of PbSe Modified Poly(p-phenylenediamine) Nanowires

摘要

In this paper, we presented a template-free method to prepare poly(p-phenylenediamine) (PpPD) nanowires. PpPD nanowires were synthesized by chemical oxidative polymerization in aqueous solution, using ammonium persulfate as initiator and β-naphthalenesulfonic acid as soft template. The obtained polymer powder was treated with Pb(NO_3)_2 and Na_2SeSO_3 solutions in sequence to form PbSe nanoparticle modified PpPD. The products were characterized by X-ray powder diffraction, infrared spectroscopy, and transmission electron microscopy, respectively. The thermoelectric properties of the powders after cold pressing were measured at room temperature. The pure dedoped PpPD nanowires exhibited very large Seebeck coefficient (2692 μV K~(-1)) but very low electrical conductivity. As the PbSe content increased, the electrical conductivity of the PbSe/PpPD composite increased, whereas the Seebeck coefficient decreased, and the power factor monotonically increased. The sample with 41.5 wt% PbSe had a highest power factor, 0.189 μW m~(-1) K~(-2), which is ～270 times as large as that of the pure PpPD nanowires (8.7 × 10~(-4) μW m~(-1) K~(-2)).