Benevolent behavior of Kleinia grandiflora leaf extract as a green corrosion inhibitor for mild steel in sulfuric acid solution

• Published in: International journal of minerals, metallurgy and materials Vol. 21; no. 11; pp. 1083 - 1095
• Main Authors: Pitchaipillai, Muthukrishnan, Raj, Karthik, Balasubramanian, Jeyaprabha, Periakaruppan, Prakash
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.11.2014; Springer Nature B.V
• Subjects: Adsorption; Carbon steels; Ceramics; Characterization and Evaluation of Materials; Charge transfer; Chemistry and Materials Science; Composites; Corrosion; Corrosion and Coatings; Corrosion effects; Corrosion inhibitors; Corrosion prevention; Electrochemical impedance spectroscopy; Electrochemistry; Extractive metallurgy; Fourier transforms; Free energy; Glass; Green chemistry; Impedance; Infrared analysis; Infrared spectroscopy; Inhibition; Langmuir; Low carbon steels; Materials Science; Metallic Materials; Natural Materials; Plant extracts; Polarization; Spectrum analysis; Steel; Sulfuric acid; Surfaces and Interfaces; Temperature effects; Thin Films; Tribology; X-ray diffraction; 低碳钢; 傅立叶变换红外光谱仪; 叶提取物; 玉兰; 硫酸溶液; 绿色缓蚀剂; 腐蚀行为; steel corrosion; sulfuric acid; corrosion inhibitors; mild steel
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-014-1013-7

The ethanolic extract of Kleinia grandiflora leaves was characterized and tested for its potential anticorrosion properties on mild steel in 1 M H2SO4 medium using mass-loss analysis, potentiodynamic polarization measurements, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, UV–visible spectroscopy, and X-ray diffraction analysis. The effect of temperature on the corrosion behavior of mild steel was studied in the range of 308 to 328 K. The inhibition efficiency was observed to increase with increasing concentration of the extract. Polarization curves revealed that the Kleinia grandiflora leaf extract is a mixed inhibitor. Impedance diagrams revealed that an increase of Kleinia grandiflora leaf extract concentration increased the charge transfer resistance and decreased the double-layer capacitance. The adsorption process obeys Langmuir＇s model, with a standard free energy of adsorption（ΔGads） of-18.62 k J/mol. The obtained results indicate that the Kleinia grandiflora leaf extract can serve as an effective inhibitor for the corrosion of mild steel in a sulfuric acid medium.