Selective determination of cuprous ion in copper dissolving solution based on bathocuproine-modified expanded graphite electrode

The presence of cuprous ions in the copper-dissolving solution significantly affects the microstructure of copper plated surface. Fewer quantitative analyses of cuprous ions in the copper foil productive process had rarely been involved so far. In the present work, a novel electrochemical sensor of the bathocuproine (BCP) modified expanded graphite (EG) electrode was developed for the selective determination of cuprous ions. EG has a large surface area, good adsorption, and excellent electrochemical performance which remarkably promoted analytical sensitivity. Meanwhile, the selective determination of the BCP-EG electrode for cuprous ions in the coexistence of ten thousand times of copper ions have been achieved on the benefit of the special coordination of BCP to cuprous ions. In the coexistence of 50 g/L copper ions, the analytical performance of the BCP-EG electrode for the determination of cuprous ions had been examined. The results represented a wide detection range of cuprous ions in the range of 1.0 μg/L–5.0 mg/L, with a low detection limit of 0.18 μg/L (S/N = 3) and the BCP-EG electrode has great selectivity to cuprous ions in presence of various interferences. The analytical selectively for cuprous ions supported by the proposed electrode would be a potential analytical tool for quality improvement in electrolytic copper foil manufacturing. Graphical abstract: [Figure not available: see fulltext.]