The main reason of the enhanced specific capacitance is that the introduction of PCW creates a large and electrochemically accessible internal surface area, which thus increases the double layer capacitance
. Figure 3(b) shows the CV curves of a PCW/CMP sample at various scan rates.
Reddy, "Characterization of accumulation layer capacitance
for extracting data on high-[kappa] gate dielectrics," IEEE Transactions on Electron Devices, vol.
The typical double layer capacitance
of metals and CNT in electrolyte is about the same, about 10-50 mF/[cm.sup.2], and the capacitance value can be used as a measure of electrochemically active area [23, 24].
STRATEGY OF REDUCING DOUBLE LAYER CAPACITANCE
OF DNA MODIFIED AU ELECTRODE.
The capacitive semicircle at high frequency is associated with the rust layer absorbed on the electrode surface, and the capacitive semicircle at the medium-low frequency is attributed to the double layer capacitance
and charge-transfer resistance [17, 18].
The fingers are also considered wide enough in comparison with the typical thickness of the EDL to allow for neglecting the impact of double layer capacitance
(i.e., > 1 [micro]m) :
Eventually, the circuit consists of a series connection of a solution resistance [R.sub.s] with a parallel combination of a charge transfer resistance [R.sub.ct] and a double layer capacitance
The porous electrode is described by a line of R and C elements representing the elemental double layer capacitance
and the respective electrolyte resistance at a particular pore depth.
AC impedance studies involve the measurement of the charge transfer resistance ([R.sub.ct]), the double layer capacitance
([C.sub.d1]) and the Warburg impedance ([Z.sub.w]), the parameters that constitute the proposed equivalent electrical circuit model in correlation with the behavior of coated system in a corrosive environment.
Its polarization resistance and double layer capacitance
values were also calculated.
CDL: DOUBLE LAYER CAPACITANCE
-- The coating is not the only "structural" feature of the sample that gives rise to a capacitance.
In an electrochemical cell, slow electrode kinetics, slow preceding chemical reactions, and diffusion can all impede electron flow and can be considered as comparable to the resistors, capacitors that make up the circuit in the Randles Cell, where, RW = uncompensated Resistance, Rp = polarisation resistance and CDL = double layer capacitance