Investigation of Corrosion Inhibition of Mild Steel in 0.5 M H2SO4 with Lachancea fermentati Inhibitor Extracted from Rotten Grapefruits (Vitis vinifera): Adsorption, Thermodynamic, Electrochemical, and Quantum Chemical Studies

Baluchamy Tamilselvi; Durvas Seshian Bhuvaneshwari; Periyakaruppan Karuppasamy; Sethuramasamy Padmavathy; Santhosh Nikhil; Surendra Boppanahalli Siddegowda; H C Ananda Murthy

doi:10.1021/acsphyschemau.3c00055

Investigation of Corrosion Inhibition of Mild Steel in 0.5 M H₂SO₄ with Lachancea fermentati Inhibitor Extracted from Rotten Grapefruits (Vitis vinifera): Adsorption, Thermodynamic, Electrochemical, and Quantum Chemical Studies

ACS Phys Chem Au. 2023 Dec 8;4(1):67-84. doi: 10.1021/acsphyschemau.3c00055. eCollection 2024 Jan 24.

Authors

Baluchamy Tamilselvi^{1

2}, Durvas Seshian Bhuvaneshwari¹, Periyakaruppan Karuppasamy³, Sethuramasamy Padmavathy⁴, Santhosh Nikhil⁵, Surendra Boppanahalli Siddegowda³, H C Ananda Murthy^{6

7}

Affiliations

¹ Department of Chemistry, Thiagarajar College, Madurai 625009, Tamil Nadu, India.
² Department of Chemistry, K.L.N. College of Engineering, Pottapalaiyam 630612, Tamil Nadu, India.
³ Department of Chemistry, Dayananda Sagar College of Engineering, Bangalore 560078, Karnataka, India.
⁴ Department of Microbiology and Biotechnology, Thiagarajar College, Madurai 625009, Tamil Nadu, India.
⁵ School of Chemistry, Madurai Kamaraj University, Madurai 625009, Tamil Nadu, India.
⁶ Department of Applied Chemistry, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888 Adama, Ethiopia.
⁷ Department of Prosthodontics, Saveetha Dental College & Hospital, Saveetha Institute of Medical and Technical Science (SIMATS), Saveetha University, Chennai 600077, Tamil Nadu, India.

Abstract

Corrosion inhibition of mild steel (MS) was studied using Lachancea fermentati isolate in 0.5 M H₂SO₄, which was isolated from rotten grapes (Vitis vinifera) via biofilm formation. Biofilm over the MS surface was asserted by employing FT-IR and FE-SEM with EDXS, electrochemical impedance spectroscopy (EIS), AFM, and DFT-ESP techniques. The weight loss experiments and temperature studies supported the physical adsorption behavior of the corrosion inhibitors. The maximum inhibition efficiency (IE) value (90%) was observed at 293 K for 9 × 10⁶ cfu/mL of Lachancea fermentati isolate. The adsorption of Lachancea fermentati isolate on the surface of MS confirms Langmuir's adsorption isotherm model, and the -ΔG values indicate the spontaneous adsorption of inhibitor over the MS surface. Electrochemical studies, such as potentiodynamic polarization (PDP) and EIS were carried out to investigate the charge transfer (CT) reaction of the Lachancea fermentati isolate. Tafel polarization curves reveal that the Lachancea fermentati isolate acts as a mixed type of inhibitor. The Nyquist plots (EIS) indicate the increase in charge transfer resistance (R_ct) and decrease of double-layer capacitance (C_dl) values when increasing the concentration of Lachancea fermentati isolate. The spectral studies, such as UV-vis and FT-IR, confirm the formation of a complex between MS and the Lachancea fermentati isolate inhibitor. The formation of biofilm on the MS surface was confirmed by FE-SEM, EDXS, and XPS analysis. The proposed bioinhibitor shows great potential for the corrosion inhibition of mild steel in acid media.