Electrochemical corrosion and protection of low-temperature sintered silver nanoparticle paste in NH4Cl solution

Corrosion behavior of low-temperature sintered silver nanoparticle (AgNP) paste in NH4Cl solution was investigated using electrochemical measurements (electrochemical impedance, potentiodynamic polarization, and localized electrochemical impedance spectroscopy) as well as surface characterizations (scanning electron microscope and X-ray photoelectron spectroscopy). The thiazolyl derivative was first applied as the corrosion inhibitor for the sintered AgNP paste. Results showed that the corrosion rate increased with the rising NH4Cl concentration while it decreased with the increase of solution alkaline. Due to the formation of a protective film through the coordination of N and S with Ag atoms, 2-mercaptobenzothiazole and sodium 2-mercaptobenzothiazole both showed excellent corrosion inhibition efficiencies (more than 97%) for the sintered AgNP paste in NH4Cl solutions. Relevant mechanisms have been proposed.