Electrochemical and computational investigations of the Thysanolaena latifolia leaves extract: An eco-benign solution for the corrosion mitigation of mild steel

Abstract

The development of eco-benign corrosion inhibitors is gaining increased attention due to the non-biodegradability and toxic effects of conventional inhibitors. In this study, the anti-corrosive efficacy of Thysanolaena latifolia leaves extract (TLLE) has been evaluated on mild steel in an acidic solution (0.5 M HCl) by employing various approaches including gravimetric assessment, electrochemical measurements, scanning electron microscopy and energy dispersive X-ray spectroscopy. The outcomes demonstrated that with the increased concentration of TLLE from 50 ppm to 1000 ppm, the inhibition efficiency (IE%) elevated up to 93.90 % and the corrosion rate decreased significantly from 2.513 mm/yr to 0.203 mm/yr at 298 K. Moreover, it was revealed that at a higher concentration (1000 ppm), the Rp values increased from 30.784 Ω to 157.83 Ω with an Rct in value of 159.627 Ω cm2 suggesting the defensive film formation by TLLE molecules over the metallic surface. The quantum chemical analytics further underpinned the empirical findings, showing a high ΔE(eV) value of 0.239 and interaction and binding energies of −995.45 and 995.45 for TLLE molecules upon Fe (110) substrate. The findings indicate that TLLE has a promising prospect as an eco-benign and efficient inhibitor for preventing the corrosion of mild steel in corrosive environments.

Keywords

• Thysanolaena latifolia
• Corrosion
• Mild steel
• Eco-benign extract
• Inhibition
• EIS