Electrochemical reduction process of Sb(III) on Au substrate

The electrochemical reduction mechanism of antimony on Au substrate from the solution containing Sb(III), complexing reagent tartaric acid and nitric acid was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results indicated that the reduction of Sb(III) on Au substrate was an irreversible multi-step process. The entire reduction process is completed by the following two steps: 1) The reduction of SbO⁺ and its complexing ion [(SbO)C₄H₄O₆]^- to intermediate product SbO^-; 2) The reduction of intermediate product SbO^- and its complexing ion [(SbO)C₄H₄O₆]^3- to Sb⁰. Researches also indicated that the reduction of SbO⁺ is much easier than its complexing ion [(SbO)C₄H₄O₆]^- and both SbO⁺ and its intermediate product SbO^- can adsorb on Au substrate.