The measured D AR-13324 in vivo values were found to be 7.27 × 10-8 and 1.09 × 10-7 cm2.s-1 for the PPy nanotube structure formed after 2- and 4-h etching, respectively, which is at least an order of magnitude higher than for the PPy films in 2-D porous structure [45]. These data show that homogenous transport dynamics of charge-compensating anions in the electrolyte is generally fast for 3-D PPy nanotubes especially for open interconnected PPy nanotubes formed after 4-h etch. Figure 8 Randles-Sevcik plots of PPy nanotube electrodes after 2- and 4-h etching of ZnO nanorod core. Specific capacitance C SV calculated from the CV plots using Equation 1 at different scan rates is plotted in Figure 9 for both ZnO nanorod core-PPy
sheath and PPy nanotube electrodes represented by 0-, 2-, and 4-h ZnO core etch times. The true faradic specific capacitance
due to redox processes measured at low scan rates increases dramatically when the PPy nanostructure transforms from core-sheath to nanotube. Thus, ion diffusion process in PPy nanotube structure is kinetically faster. At higher scan rates (≥50 mV.s-1), the specific capacitance on structure transformation shows moderate increase at best for electrode with open pore PPy nanotube structure obtained after a 4-h ZnO core etch. Limiting kinetics for ion diffusion is the same for PPy sheath and nanotube structures. Figure 9 Specific areal capacitance at different scan rates for ZnO nanorod core-PPy sheath PPy and PPy nanotube electrodes. Impedance spectroscopy GSK2118436 Electrochemical impedance spectroscopy (EIS) technique is extensively used
to elucidate the electrical characteristics of the electrode material and its interface with the supporting electrolyte. Frequency response of the real and imaginary impedance of the pseudocapacitive ZnO nanorod core-PPy sheath electrode with 1 M lithium perchlorate electrolyte was studied. Impedance of the electrode is a complex quantity and the extracted Atazanavir data are plotted as real (Z′) versus imaginary (Z″) impedance representing the Nyquist plot. Figure 10 shows the Nyquist plot of the as-deposited ZnO nanorod core-PPy sheath electrode in the frequency domain 0.1 MHz to 0.01 Hz and the inset shows expanded view in the high- and mid-frequency region. The capacitive component is reflected in the rapidly increasing imaginary impedance (Z″) at lower frequencies. The high-frequency real impedance (Z′) characterizes the bulk electrode and interfacial resistive properties of the electrode-electrolyte system. These parameters calculated from the impedance plots are shown in Table 1. Instead of the characteristic whole semicircle, the high-frequency Nyquist plot degenerated into an arc segment. This suggests that contribution to the bulk electrode-electrolyte PF-02341066 research buy resistance is mainly from the ZnO-PPy interface barrier due to polarization effect of the nanostructured electrode and negligible electrolyte resistance.