The corrosion behavior of the SnO2-coated mild steel in HCl solution at different temperature

Abstract

In the present work, SnO2 was successfully coated on mild steel (MS) by the sol–gel method at different times (15,30,45 min). These coatings were developed to improve the performance of corrosion protection of MS in a 0.5 M HCl solution. The morphological and structural characterization of obtained electrodes was investigated with the help of characterized by Field-emission scanning electron microscopy (FE-SEM) and the contact angle. The corrosion behavior of uncoated and at 15,30,45 min SnO2-coated MS electrodes were investigated by open circuit potential (OCP)–time, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques in 0.5 M HCl solution at 20–50 °C. Moreover, the potential of zero charges (pzc) of MS was determined using the EIS technique. EIS results indicated that the maximum inhibition efficiency (85%) during the coating time of 30 min at 30 °C. As a result, the SnO2 film effectively protected on the MS against corrosion and reduced its corrosion rate in the HCl solution. Highlights The SnO2 was coated on MS electrode at 15, 30, 45 minutes by a simple sol-gel method. The surface morphologies were characterized by FE-SEM and the contact angle. The corrosion behaviors of samples were investigated by electrochemical techniques. The SnO2 provides good corrosion protection against the attack of corrosive media.