Facile Synthesis and Electrochemical Characterization of Polyaniline@TiO2-CuO Ternary Composite as Electrodes for Supercapacitor Applications.

This research reports the facile, controlled, low-cost fabrication, and evaluation of properties of polyaniline matrix deposited on titanium dioxide and copper(II) oxide ternary-composite (PANI@TiO2-CuO)-based electrode material for supercapacitor application. The process involves the preparation of CuO in the presence of TiO2 to form TiO2-CuO by a facile method, followed by in-situ oxidative polymerization of aniline monomer. The structural and physical properties were evaluated based on the results of FTIR spectroscopy, X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), transmission electron (TEM) and scanning electron (SEM) microscopy, thermogravimetric analysis (TGA), and BET surface areas analysis. The results indicated that TiO2-CuO was dispersed uniformly in the PANI matrix. Owing to such dispersion of TiO2-CuO, the PANI@TiO2-CuO material exhibits dramatic improvements on thermal stability in comparison with the pure PANI. The cyclic voltammetry (CV) confirms the reversibility of PANI redox transitions for this optimized electrode material. Moreover, the results reveal that the specific capacitance of PANI@TiO2-CuO reaches 87.5% retention after 1500 cycles under 1.0 A g-1, with a better charge storage performance as compared to pure PANI and PANI@TiO2 electrodes. The preparation of PANI@TiO2-CuO with enhanced electrochemical properties provides a feasible route for promoting its applications in supercapacitors.

Reactive Insertion of PEDOT-PSS in SWCNT@Silica Composites and its Electrochemical Performance.

Hybrid silica-modified materials were synthesized on glassy carbon (GC) electrodes by electroassisted deposition of sol-gel precursors. Single-wall carbon nanotubes (SWCNTs) were dispersed in a silica matrix (SWCNT@SiO2) to enhance the electrochemical performance of an inorganic matrix. The electrochemical behavior of the composite electrodes was tested against the ferrocene redox probe. The SWCNT@SiO2 presents an improvement in the electrochemical performance towards ferrocene. The heterogeneous rate constant of the SWCNT@SiO2 can be enhanced by the insertion of poly(3,4-Ethylendioxythiophene)-poly(sodium 4-styrenesulfonate) PEDOT-PSS within the silica matrix, and this composite was synthesized successfully by reactive electrochemical polymerization of the precursor EDOT in aqueous solution. The SWCNT@SiO2-PEDOT-PSS composite electrodes showed a heterogeneous rate constant more than three times higher than the electrode without conducting polymer. Similarly, the electroactive area was also enhanced to more than twice the area of SWCNT@SiO2-modified electrodes. The morphology of the sample films was analyzed by scanning electron microscopy (SEM).