In Situ Electrodeposition of Pb and Ag Applied on Fluorine Doped Tin Oxide Substrates: Comparative Experimental and Theoretical Study

Abstract

A comparison between lead and silver electrodeposition onto fluorine-doped tin oxide (FTO) electrodes from nitrate solution was investigated in this work. Chronoamperometry has been used as an in situ technique to track the dynamics of the electrodeposition during advanced nucleation phases. The experimental results are correlated with a theoretical evaluation. It has shown that they have a strong correlation with each other. After that, the obtained deposits are characterized and compared as well by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), and impedance spectroscopy. The data reflects the effect of the material under investigation on current density, deposition density, and dielectric properties. Additionally, the electrodeposition approach (a two-in-one technique) can be followed in order to make well-controlled thin films that can be used for various purposes in addition to recovering heavy metals from wastewater.

Keywords: X-ray diffraction FTO; impedance spectroscopy; in situ electrodeposition; lead; silver.

Figure 1

Electrodeposition scheme of the electrodeposition workstation: WE; working electrode, RE; reference electrode, CE; counter electrode.

Figure 2

Cyclic voltammogram: black color free solution, red and blue colors presence of Ag and Pb in an aqueous solution, respectively. Scan speed is 60 mV/s.

Figure 3

(a) Ag and (b) Pb electrodeposition current density versus time and their best fit according to Equation (2).

Figure 4

The electrical equivalent circuit for the sample being tested is shown in the inset, along with the associated Nyquist plots. The red line represents the best fit based on this circuit, while the scatter points represent the experimental results (a) Silver and (b) Lead.

Figure 5

Bode plots: scatter points present the experimental magnitude Bode plot and phase angle Bode plot for lead and silver. Red line represents their best fit based on the equivalent circuit shown in Figure 4.

Figure 6

SEM images of (a) Ag and (b) Pb deposed on FTO substrate.

Figure 7

Energy dispersive X-ray analysis spectrum of (a) silver and (b) lead deposit on FTO substrate.

Figure 8

Plots of the Rietveld refinement given the comparison of the experiment with the calculated XRD patterns of (a) Ag and (b) Pb.