Electrochemical Detection of Iron in a Lixiviant Solution of Polluted Soil Using a Modified Glassy Carbon Electrode

Table 1

Real area values obtained from capacitance current calculations of the different electrodes, and thermodynamic parameters of the electroreduction of iron over the different electrodes used, in 0.1 M KCl at 298 K: (A) Glassy Carbon Electrode, (B) Glassy Carbon Electrode-Multiwalled Carbon Nanotubes, (C) Glassy Carbon Electrode-Multiwalled Carbon Nanotubes-Polyanaline, (D) Glassy Carbon Electrode-Platinum nanoparticles, (E) Glassy Carbon Electrode-Multiwalled Carbon Nanotubes-Platinum nanoparticles, and (F) Glassy Carbon Electrode-Multiwalled Carbon Nanotubes-Polyanaline-Platinum nanoparticles.

	Equation	𝑅^2	𝐶dl/μF cm^−2	𝐴real/cm^2	Δ𝐸𝑝	|𝑖pc|/|𝑖pa|	Process
A	𝑖cap=8×10^−5𝑣+1×10^−5	0.6868	8 × 10^−5	1.33	—	—	Irreversible
B	𝑖cap=6×10^−5𝑣+3×10^−6	0.7380	6 × 10^−5	1.00	0.525	0.94	Quasireversible
C	𝑖cap=4×10^−5𝑣+7×10^−6	0.9713	4 × 10^−5	0.67	0.176	1	Quasireversible
D	𝑖cap=1×10^−4𝑣+2×10^−5	0.9256	1 × 10^−4	1.67	0.194	0.46	Quasireversible
E	𝑖cap=3×10^−4𝑣+9×10^−7	0.8096	3 × 10^−4	5.00	0.610	0.90	Quasireversible
F	𝑖cap=8×10^−6𝑣+1×10^−5	0.9333	8 × 10^−6	0.13	0.578	0.88	Quasireversible