Fabrication of polyaniline nanowire/TiO2 nanotube array electrode for supercapacitors

Abstract

A per literature study, work of PANI (polyaniline) nanowire/TiO2 nanotube arrays with highly porous structures and good capacitive characteristics are not prepared by electrochemical methods. The authors have described the TiO2 nanotube arrays which are fabricated by simple anodization of Ti sheet in ammonium fluoride/glycerol solution. PANI nanowires were deposited on the TiO2 nanotube layer by electro-polymerization. TiO2 nanotube layer to promote the formation of a concentration gradient of aniline monomer, and thus indirectly played a role in the dynamic template. Structural and morphological characterizations indicate that the PANI nanowires and TiO2 nanotubes have diameters of 200–300 nm and 60–100 nm, respectively. The intricate cooperation of the two materials enables the supercapacitor to work in a widened 1.2-V potential window. The specific capacitance of these electrodes is around 897.35 F g−1 at a current density of 0.21 A g−1 in 0.05 M H2SO4. The modified electrodes also show high cycling stability and maintain 86.2% of the initial capacity after 1500 cycles. The coexistence of mesopores, nanowires, and nanotubes favors the fast penetration of the electrolyte, facilitates ion diffusion, and shortens the charge transfer distance, all of which lead to the superior electrochemical performance of PANI nanowire/TiO2 nanotube arrays.