Morphology-dependent electrochemical supercapacitors in multi-dimensional polyaniline nanostructures

Although some polyaniline (PANI) morphologies have been reported, their synthesis with regular structures in multiple dimensions has met with limited success. Here, well-defined PANI spheres, roses, cloud-like and rhombic plates, layered flowers, columns, blocks, and dendrites were prepared by employing static surfactant systems in a 0.010 M HCl solution at room temperature. The acquisition of these multi-dimensional (MD) nanostructures was a result of the fact that aniline and the newly formed PANI molecules were subjected to a synergistic effect of soft templates and self-assembly processes. Detailed electrochemical measurements were performed to investigate the capacitance of these MD nanostructures. PANI layered flowers possessed the highest specific capacitance of 272 F g^-1 at the current density of 1.0 A g^-1 due to their morphologies. Additionally, two factors including the surfactant dosage and the pH value were evaluated to discern their impacts on the PANI morphologies. The method presented herein renders the possibility for fabricating regular MD PANI nanostructures. And these nanostructures also have potential to be applied in supercapacitor electrodes and energy storage.