Multiple-scan voltammetry of immobilized particles of ancient copper/bronze coins

The application of a multiple-scan strategy to study the structure of the corrosion patina of copper/bronze ancient objects using the voltammetry of immobilized microparticles (VIMP) is described. Upon nanosample attachment to graphite electrodes in contact with aqueous acetate buffer, voltammetric signatures characterizing cuprite with variable degree of crystallinity are recorded by means of successive cathodic scans reflecting the composition of the corrosion patina. The reported methodology, complemented with ion beam-field emission scanning electron microscopy (FIB-FESEM) and high-resolution field emission scanning electron microscopy (HRFESM-EDX), is applied to a set of coins fabricated between 1709 and 1962 revealing different corrosion patterns.