Large-Area Polyaniline Nanorod Growth on a Monolayer Polystyrene Nanosphere Array as an Electrode Material for Supercapacitors

The high utilization efficiency of electrode materials is an important strategy to achieve good electrochemical performance for supercapacitors. In this article, the Langmuir–Blodgett technique had been introduced to arrange the aminated polystyrene (PS) nanospheres on fluorine-doped tin dioxide (FTO) conducting glass to form a support substrate with a monolayer array structure, and then, the nanorod-like polyaniline (PANI) in situ grew onto the surface of PS nanospheres by dilute solution polymerization to form a usable PANI@PS/FTO electrode for supercapacitors. The aminated PS nanospheres could easily adsorb more aniline molecules, which provided a convenient path for the penetration of the reaction solution so that PANI nanorods could directly in situ grow onto the surface of PS nanospheres. Since the PANI@PS array structure was completely exposed to the electrolyte, the PANI nanorods exhibited an efficient utilization rate, resulting in a high specific capacitance as high as 753 F/g (1 A/g). The PANI@PS/FTO electrode showed a high rate capability due to the fact that the monolayer sphere array structure allowed the ions to easily penetrate from the electrolyte to the active electrode material. The capacitance retention was as high as 69.2% along with the current density increasing from 1 to 5 A/g. The capacitance retention of the long-life cycle stability of the PANI@PS/FTO electrode was about 85.5% after 1000 cycles. The above calculated performance parameters were close to or much better than those of previous studies.