Electrochemical and statistical study of the inhibition effect of T. conophorum leaf extract on aluminum corrosion in acidic medium

• DOI: 10.1007/s42797-021-00040-2
• Publication Date: 2021-08-30T04:12:21Z
• Authors: Loveth N. Emembolu; Chukwunonso O. An...; Josiah C. Umembamalu; Chukwunonso N. On...
• Keywords: Quadratic model; Corrosion inhibitor

This work investigated the corrosion inhibition ability of T. conophorum leaf extract (TCLE) on aluminium in a 3 mol/L HCl medium using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The effect of four process variables (acid conc., inhibitor conc., corrosion time and temperature) on the inhibition efficiency was optimized using Response Surface Methodology (RSM) techniques. The Tafel plot reveals the effectiveness of TCLE act as a mixed-type inhibitor, with relatively high inhibition efficiency (>70%). The optimal inhibition efficiency was determined at acid conc: 1.5 mol/L, inhibitor conc: 0.04 g/L, corrosion time: 4.5 h and temperature: 303 K. Analysis of variance (ANOVA) result confirmed the fitting goodness of quadratic regression model, with a models’ probability (p values), Fischer’s F-value, and lack-of-fit values of 0.0001, 15.76 and 0.999, respectively. Hence the corrosion data were well described by the quadratic model, as it presented sufficient forecasting of the optimal inhibitory conditions.