Electrochemical data on the corrosion inhibition performance of admixed Citrus paradisi and Zingiber officinale oil extracts in 0.5 M H2SO4 solution

Abstract

Data output on the protection performance of the combined admixture of Citrus paradisi and Zingiber officinale oil extracts (CPZO) on the corrosion inhibition of mild steel in 0.5 M H2SO4 solution are presented and described. CPZO effectively suppressed the electrochemical reactions on the steel surface with final inhibition values ranging between 95.16 mm/y at 1 % CPZO and 96.61 % at 3.5 % CPZO concentration. CPZO reduced the corrosion rate of the steel from the value of 184.48 % at 0 % CPZO concentration to values between 3.45 mm/y and 8.94 mm/y in the presence of CPZO extract. CPZO performance remained marginally steady with respect to its concentration. However, variation with time was significant till 240 h. Effective inhibition performance was attained at 48 h of exposure. Calculated data from ANOVA analysis shows exposure was the only statistically relevant parameter at 98.63 % compared to 0.75 % for CPZO concentration. Adsorption of CPZO molecules on the steel aligns with the Langmuir and Frumkin isotherm models with correlation coefficient values of 0.9997 and 0.7292. Thermodynamic calculations depict chemisorption adsorption mechanism with ΔG values ranging between −46.13 and −43.23 KJ/mol. Optical images of the inhibited and non-inhibited steel significantly contrast each other.