Square Wave Anodic Stripping Voltammetry Applied to a Nano-Electrode for Trace Analysis of Pb(II) and Cd(II) Ions in Solution

Antonino Scandurra,Salvo Mirabella

doi:10.1109/jsen.2021.3051762

Abstract

In this work we describe the Square Wave Anodic Stripping Voltammetry (SWASV) electrochemical technique for the determination of lead (Pb 2+ ) and cadmium (Cd 2+ ) metal ions at concentration of sub-part per billion (ppb) in aqueous solution. Moreover, simple and low-cost procedures for the fabrication of high performance working nano-electrode are reported. The electrode structure consists of a graphene paper (GP) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$240~\mu \text{m}$ </tex-math></inline-formula> thick with the function of electrical conductor and substrate, a layer of nafion 0.5- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.7~\mu \text{m}$ </tex-math></inline-formula> thick onto the graphene paper and bismuth nanoparticles embedded in the nafion thin layer. The bismuth nanoparticles were fabricated by electrodeposition starting from Bi(III) ions, employing a key step of hydrogen ions of nafion <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}^{\mathbf {+}}$ </tex-math></inline-formula> exchange with bismuth ions Bi(III). This procedure is aimed to improve the bismuth nanoparticles concentration. The SWASV applied to the low-cost nanoelectrode allows detecting Pb 2+ and Cd 2+ at concentration as low as 0.1 ppb.

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