Inhibitory Action of Artemisia annua Extracts and Artemisinin on the Corrosion of Mild Steel in H2SO4 Solution

The action of ethanol (EEAA), acid (AEAA), and toluene (TEAA) extracts from Artemisia annua and Artemisinin (ATS) on mild steel corrosion in H2SO4 solutions was investigated using gravimetric and gasometric techniques. The extracts and ATS functioned as good inhibitors, and their inhibition efficiencies (%IE) followed the trend: EEAA > AEAA > TEAA > ATS. %IE increased with increase in inhibitors concentration and decreased with increase in temperature. The enhanced %IE values of the extracts were attributed to synergistic effect of the components of the plant extracts with ATS. The adsorption of the inhibitors was consistent with Langmuir isotherm. Physisorption is proposed as the mechanism of inhibition.