Preparation and Electrochemical Properties of Polyaniline Nanostructures Using Vertically Aligned Mesochannels as Confinement

One-dimensional conducting polymer nanowire arrays have shown promising potential in applications of electrochemical supercapacitors, sensors, and more. Herein, vertically aligned mesoporous silica films (VMSF) with hexagonally packed mesochannels were generated on indium-tin oxide (ITO) electrodes by an electrochemically-assisted self-assembly (EASA) method. The prepared VMSF/ITO electrode was then exploited as a hard template for electrochemical growth of well-aligned polyaniline (PANI) nanofilaments within silica mesochannels, eventually forming a PANI/VMSF/ITO composite electrode. The electrochemical conditions of the PANI growth through the mesochannnels were investigated in detail, and the electrochemical capacitance was also tested. It is shown that the resulting nanofilaments separated through silica walls exhibit significantly improved electrochemical performance, including better electrochemical reversibility and high specific capacitance (3.00 mF/cm(2) at 20 mu A/cm(2)), which is increased by about 152 % in comparison to PANI directly on an ITO (PANI/ITO) substrate. Such an improved electrochemical performance is mainly contributed to by enhanced charge transfer efficiency and improved electrochemical reaction kinetics resulting from the well-aligned PANI nanostructure.