Highly Conductive Polypyrrole/γ-Fe2O3 Nanospheres with Good Magnetic Properties Obtained through an Improved Chemical One-Step Method

An improved chemical one-step method (ICOSM) was used to prepare highly conductive and magnetic polypyrrole/gamma-Fe2O3 (PPy/gamma-Fe2O3) nanospheres similar to 80 nm in diameter. In the reaction process involved, FeCl3 acts as an oxidant for the polymerization of pyrrole and as a source of Fe-III for the formation of gamma-Fe2O3, which also requires the initial presence of Fe-II, provided by the addition of FeCl2. The method differs from the previous chemical one-step method (COSM) through the addition of p-toluenesulfonic acid (p-TSA) as the dopant after addition of the FeCl3 solution was finished. The conductive and magnetic properties of PPy/gamma-Fe2O3 nanospheres increased and reached maximum values simultaneously with increasing amounts of FeCl2, contrary to the result observed in the previous COSM. The resulting electromagnetic PPy/gamma-Fe2O3 nanospheres show maximum conductivity of 64.4 S/cm and saturation magnetization of 4.85 A m(2)/kg. The p-TSA dopant plays a critical role in the formation of PPy/gamma-Fe2O3 nanospheres.