Berberis Aristata: A Highly Efficient and Thermally Stable Green Corrosion Inhibitor for Mild Steel in Acidic Medium

Plant extracts are extensively researched as a source of green corrosion inhibitors. Herein, we report on a highly efficient and thermally stable corrosion inhibitor from the stem extract of high-altitude shrub Berberis aristata. The corrosion inhibition efficiency (IE) of the extract was tested in 1.0 M H2SO4 for the corrosion protection of mild steel (MS) by using gravimetric and electrochemical measurements. It displayed a remarkable IE of 90% at 200 ppm and reached to 98.18% at high concentration (1000 ppm) at room temperature. The thermal stability of the adsorbed extract was uncommon among the recently reported plant extracts, giving an IE of 80% at 338K. Besides, the adsorption of the extract was extremely efficient, producing an IE of 90% in 15 min. The thermodynamic parameters (ΔG and Ea) showed a chemisorption dominated behavior of the extract. Electrochemical measurements indicated a mixed type of inhibitor, and the extract suppressed the corrosion rate by blocking the active surface of the MS.