Alignment of polyaniline nanofibers on 3-D templates: “Hairy” hollow microspheres as high-performance pseudocapacitive materials

A facile method was developed for growing the alignment of polyaniline (PANI) nanofibers on three-dimensional (3-D) templates, via the chemical oxidative polymerization of aniline in dilute solution at 0–5 °C in presence of sulfonated polystyrene (SPS) microspheres and hydrochloric acid as template and dopant, respectively. Then the “hairy” PANI hollow microspheres were obtained after etching the templates with toluene. It was found that the formation of the “hairy” PANI hollow microspheres could be well controlled by altering the template concentration, thus the possible formation mechanism was deduced. The unique “hairy” PANI hollow microspheres prepared with the template concentration of 2.0 mg mL−1 possessed the specific capacitance of 298 F g−1 and the capacitance retention of 63.6% after 900 cycles.