Synthesis of polyaniline-titania nanotube arrays hybrid composite via self-assembling and graft polymerization for supercapacitor application

In this work, polyaniline-γ-aminopropyltriethoxysilane-titania nanotube arrays (PANI-APTES-TiO2 NTA) nanocomposite was synthesized through a graft polymerization of PANI on the surface of the self-assembled monolayer (SAM) coated TiO2 NTA, after anodized TiO2 NTA was modified by APTES. The morphology and structure of nanocomposite was characterized by FESEM and FTIR, respectively, and its electrochemical performance was measured by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge. The microstructure of PANI-APTES-TiO2 NTA could be clearly observed that PANI nanowires grew vertically from inside of TiO2 NTA. PANI-APTES-TiO2 NTA PANI-APTES-TiO2 NTA showed better electrochemical behavior than that of PANI-TiO2 NTA. The maximum specific capacitance of PANI-APTES-TiO2 NTA was 380 F g−1 at current density of 0.5 A g−1, which specific capacitance retention ratio was circa 74.4% when the current density was increased by 20 times. After constant charge-discharge 1000 cycles, the specific capacitance of the PANI-APTES-TiO2 NTA retained 90.5% of the initial specific capacitance at current density of 5 A g−1. The good electrochemical performance was attributed to the anchoring function of APTES and support of TiO2 NTA.