Work

2,2′-Biquinoline Modified Expanded Graphite Electrode for the Detection of Cuprous Ions in Electrolytic Copper Foil Electrolyte

Year: 2026

Type: article

Abstract: The coexistence of Cu in copper sulfate electrolyte significantly affects the microstructure and performance of the copper foil. So far, there has been little quantitative analysis of Cu+ in the electrolyte during the copper foil production process. This paper fabricated a 2,2′-Biquinoline (BIQ) modified expanded graphite (EG) electrode electrochemical sensor for the selective determination of Cu+. EG, with its large specific surface area and excellent adsorption and electrochemical properties, significantly enhances analytical sensitivity. Additionally, BIQ’s specific coordination with Cu+ improves the sensor’s rapid and effective quantification of Cu+ in the electrolytic copper foil electrolyte. The linear equation of this sensor is I = 0.03769 + 0.29997 × c (R2 = 0.9989), with a detection limit of 8 μg/L (S/N = 3). The BIQ-modified EG electrode has good selectivity for Cu+, with a recovery rate for cuprous ions of 101.00% to 105.00% under the coexistence of 10,000 times Cu2+, and an RSD of less than 2%. This sensor’s efficient, sensitive, and selective detection of Cu+ can be an effective method to improve the quality of electrolytic copper foil products.

Source: Materials

DOI: 10.3390/ma19030586