Electrochemical Detection of Pb²⁺ Ions in Aqueous Solution Based on Pb²⁺/PbO₂ Redox Process Using Diamond Electrode

Abstract

Boron-doped conductive diamond electrode showed a high response to Pb²⁺/PbO₂ redox system in HNO3 aqueous solution. A cathodic current peak due to the reduction of PbO₂ to Pb²⁺ was clearly observed on the diamond electrode in the cathodic potential scan after the anodic oxidation at 1.80V vs. saturated calomel electrode (SCE) for 10min in the solution containing Pb²⁺ ions. A linear relation between the magnitude of cathodic current peak and the concentration of Pb²⁺ (1-10μmo·dm^-3) was obtained without interference of other metal ions (Cu²⁺, Fe³⁺, Ni²⁺, Mn²⁺) coexisting.