A comprehensive study on crude methanolic extract of Artemisia pallens (Asteraceae) and its active component as effective corrosion inhibitors of mild steel in acid solution

► Arbutin, an active principle from Artemisia pallens as corrosion inhibitor. ► Inhibition performance ascertained by weight loss. ► Mechanism of activity determined by EIS, XPS, FTIR, and Raman spectroscopy. ► Inhibition efficiency found 98% (crude extract), 93% (arbutin) at 400mgl−1. Corrosion inhibition effects of crude methanolic extract of Artemisia pallens on mild steel in 1moll−1 HCl were studied by weight loss and electrochemical technique. Arbutin, an active principle from A. pallens and the crude methanolic extract exhibited inhibition efficiency of 93% and 98% in 400mgl−1 concentration at 30°C respectively. The results indicated that arbutin in acidic medium acted as good anti-corrosive agent synergistically with its hydrolyzed products hydroquinone and d-glucose. Adsorption of both the inhibitors on mild steel surface conformed to the Langmuir isotherm with standard adsorption free energy of −33.07kJmol−1 for arbutin.