This article exposes a facial approach to self-assemble polyaniline (PANI) nanowires with thin diameter (similar to 10 nm) and high room-temperature conductivity (similar to 10(0) S/cm) by using Fe-2(SO4)(3) as a binary oxidant and dopant. The new method not only saves hard templates and postprocess of template removal but also simplifies the reagent. Formation yield, diameter, and room-temperature conductivity of the nanowires are affected by the molar ratios of Fe-2(SO4)(3) to aniline. The low redox potential of Fe-2(SO4)(3) not only results in a thinner diameter and higher room-temperature conductivity (10(0) S/cm) of the nanowires but also shows a much weaker temperature dependence of resistivity and smaller characteristic Mott temperature (T-0 = 2.5 x 10(3) K).