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 153,045 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.

在当前工作中，通过溶胶-凝胶法在不同时间（15、30、45分钟）成功地将SnO ₂涂覆在低碳钢（MS）上。开发这些涂层的目的是改善在0.5 M HCl溶液中MS的腐蚀防护性能。借助于场发射扫描电子显微镜（FE-SEM）和接触角对所得电极的形态和结构进行了研究。SnO ₂在15、30、45 min时未涂层的腐蚀行为在20–50°C的0.5 M HCl溶液中，通过开路电势（OCP）-时间，电化学阻抗谱（EIS）和恒动力极化技术研究了涂有MS的电极。此外，使用EIS技术确定了MS的零电荷（pzc）势。EIS结果表明，在30°C下30分钟的涂覆时间内最大抑制效率（85％）。结果，SnO ₂膜可有效保护MS免受腐蚀并降低其在HCl溶液中的腐蚀速率。

• 强调

• SnO ₂通过简单的溶胶-凝胶法在153,045分钟处涂在MS电极上。

• 用FE-SEM和接触角表征表面形貌。

• 用电化学技术研究了样品的腐蚀行为。

• SnO ₂提供了良好的腐蚀防护，可抵抗腐蚀性介质的侵蚀。