Properties and chemical oxidation polymerization of polyaniline/neutral red/TiO2 composite electrodes

Polyaniline/neutral red/TiO2 composite electrode materials (PANI/PNR/TiO2) are prepared by chemical oxidation polymerization. Structural and morphological characterizations of PANI/PNR and PANI/PNR/TiO2 are carried out by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results reveal a uniform dispersion of TiO2 nanoparticles in the netlike structure of PANI/PNR structure. Electrochemical performance of the composite electrodes is studied by cyclic voltammetry, ac impedance spectroscopy and galvanostatic charge-discharge measurements in 1 M H2SO4 solution. The results indicate that PANI/PNR/TiO2 composite electrodes show high specific capacitance and good cyclic stability. The maximum specific capacitance of 335 F g−1 is obtained from galvanostatic charge-discharge at a constant current of 5 mA, the specific capacitance of PANI/PNR/TiO2 composite has improvement values of 22% compared to that of PANI/PNR (260 F g−1). Besides, PANI/PNR/TiO2 supercapacitors show excellent cyclic performance; the decay of the capacitance after 1000 charge-discharge cycles is only 20%.