Investigation of Sn–Zn electrodeposition from acidic bath on EQCM

Tin–zinc (Sn–Zn) alloy with low tin content was deposited on gold electrode and steel substrate with use of chronoamperometric technique from an acidic bath. In order to evaluate coating efficiency of Sn–Zn alloy in 0.5 M NaCl solution, open circuit potential–time curve (EOCP–t), polarization curves, mass change of the electrode (Δm–t) using quartz crystal microbalance (QCM) were compared to those of pure Sn and Zn coatings. Anodic stripping measurements were carried out simultaneously with the mass loss of the deposit. Scanning electron microscopy (SEM) and energy dispersive X-ray spectra (EDS) analysis were performed to characterize the surface morphology. Anodic stripping experiment and EDS analysis indicated that Sn, Zn, and SnO2 formed on the electrode surface when Sn–Zn was coated from acidic bath. Furthermore, local mapping demonstrated homogeneous distribution of Sn and Zn atoms throughout the surface.

Research highlights▶ Sn–Zn alloy was electroplated from acidic bath with low Sn content. ▶ We evaluate Sn–Zn alloy coating efficiencies in 0.5 M NaCl using EQCM techniques and SEM. ▶ Sn–Zn alloy give higly satisfactory results regarding to protection of steel in acidic bath. Sn is coat as Sn and SnO2 nanoparticles.