Corrosion inhibition of copper in neutral chloride media by a novel derivative of 1,2,4-triazole

Highlights: → Bis-(4-amino-5-mercapto-1,2,4-triazol-3-yl)-butane (BAMTB) used as a corrosion inhibitor for copper in neutral NaCl media. → Excellent efficiency, even better than benzotriazole. → A thin protective film with a copper-sulfur bond is responsible for the good inhibition. - Abstract: The efficiency of a new corrosion inhibitor, the bis-(4-amino-5-mercapto-1,2,4-triazol-3-yl)-butane (BAMTB), on copper was investigated in an aerated 3% NaCl solution using various techniques. Voltammetry, chronopotentiometry and electrochemical impedance spectroscopy (EIS) were performed to evaluate the inhibition efficiency of BAMTB. The surface layers were also characterized by Raman micro-spectroscopy and by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX). Potentiodynamic polarization curves showed that BAMTB is a mixed-type inhibitor for copper in neutral chloride solution and is even more efficient than the reference compound benzotriazole.