Electrochemical sensor for thiourea focused on metallurgical applications of copper

A simple and reliable device is presented for the direct monitoring of thiourea in copper electrorefinery baths as a tool for reconditioning of industrial baths, and so reducing its environmental impact. For this purpose, a screen-printed graphite electrode is modified with silver nanoparticles (AgNPs) contained in a polyelectrolyte-surfactant matrix. The AgNPs are able to adsorb the thiourea, improving the sensitivity of the electrode toward this analyte, even in the presence of usual additives (Avitone and glue). The system allows the determination of thiourea in a range of 1-10 mg/L. A coupled electrochemical and IR analysis is proposed to evaluate the involved mechanism. (C) 2016 Elsevier B.V. All rights reserved.