VOLTAMMETRIC INVESTIGATIONS OF THE EFFECT OF TRITON X-100 ON COPPER PROCESSES IN THE PRESENCE OF OXYGEN

The influence of Triton X-100 (T-X-100) on the redox processes of copp er in NaCl solutions and in the presence of oxygen was investigated by anodic stripping alternating current voltammetry (ASacV), anodic stri pping direct current voltammetry (ASdcV), and differential pulse anodi c stripping voltammetry (DPASV). In the presence of oxygen, copper dis solution from amalgam is characterized by a catalytic process, resulti ng in a net cathodic current due to the oxidation of Cu(I) to Cu(II) b y H2O2, formed on the electrode, and the subsequent reduction of Cu(II ) back to-Cu(I). Triton X-100 blocks the catalytic process by hinderin g the formation of H2O2, by competing with CuCl2- and Cl- for the adso rption sites on HMDE surface, and by blocking the formation of Cu(I) a nd Cu(II) hydroxide deposit on the surface. Its presence also changes the redox processes of copper from reversible to quasireversible. At t he same time, T-X-100 increases the oxidation current of copper, proba bly through disproportionation of Cu(I) to Cu(0) and Cu(II). This last effect was observed regardless of whether oxygen was present in the s olutions or not.