The water-dispersed conductive polypyrrole (PPy) nanoparticles were prepared via the chemical oxidative
polymerization with fulvic acids (FAs), a renewable resource from both soils and municipal waste compost,
as dopant and stabilizer for tuning the properties of polypyrrole nanoparticles. The FA-doped polypyrrole
(PPy/FAs) nanoparticles were characterized with Fourier transform infrared (FTIR), UV vis, thermogravi-
metric analysis (TGA), transmission electron microscopy (TEM), and electric conductivity. The diameters
of the PPy/FAs nanoparticles decreased from (150 to 20) nm with the increasing of the feeding ratio of
FAs, and the PPy/FAs nanoparticles could be well-dispersed in water. Their electrical conductivities were
affected markedly by the amount of the natural dopant added. They have weakly temperature-dependent
conductivity over the entire temperature interval from (283 to 423) K.