Fabrication of polyaniline/graphene/titania nanotube arrays nanocomposite and their application in supercapacitors

•The PANI/graphene/TiO2 nanotube arrays were fabricated firstly.•The composite shows a high specific capacitance and superior rate capability.•A high capacity retention rate of 91% after 1000 cycles can be achieved.•The composite possesses a novel three-dimensional (3D) highly ordered nanostructure.•TiO2 NTs enhance the adhesion between PANI and substrate.

Polyaniline/graphene/titania nanotube arrays (PGTNs) nanocomposite as a supercapacitor electrode is fabricated by in-situ polymerization for the first time. Herein, the PGTNs possesses a novel three-dimensional (3D) highly ordered hybrid nanostructure consisting of coaxial polyaniline (PANI)/TiO2 nanotube arrays and graphene coated with PANI on the surface of TiO2 in some degree. The synthesized three-dimensional PGTNs is characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Raman spectroscopy, and its electrochemical performance is measured by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge. The maximum specific capacitance of PGTNs is as high as 933 F g−1 at current density of 0.75 A g−1 and the specific capacitance retains 91% of the initial after constant charge–discharge 1000 cycles. The improved electrochemical performance is due to the 3D nanostructure, which effectively prevents the mechanical deformation during the fast charge/discharge process and favors the diffusion of the electrolyte ions into the inner region of active materials. The composite electrode material is very promising for the next generation of high-performance electrochemical supercapacitors.

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