Strychnos nux‐vomica an eco‐friendly corrosion inhibitor for mild steel in 1 M sulfuric acid medium

The inhibition efficiency of the extract of Strychnos nux‐vomica for the corrosion of mild steel in 1 M sulfuric acid was investigated using weight loss test (carried out at 303–323 K), electrochemical measurement, and scanning electron microscope (SEM). The results of weight loss studies indicated that the inhibition efficiency increased with inhibitor concentration and the temperature of the system (following Temkin adsorption isotherm). Electrochemical studies proved that the inhibitor acts through mixed mode of inhibition and the inhibitor molecules adsorb on the metal–solution interface. SEM studies supported the adsorption of the inhibitor over the metal surface. The possible active ingredient responsible for the anticorrosion effect is identified as brucine which is isolated and screened for the anticorrosion effect using electrochemical studies and quantum chemical studies. The possible mode of corrosion inhibition of brucine is also derived using FT‐IR studies.