Evaluation of adsorption and corrosion inhibition properties of Solanum Macrocarpon leaves extract on mild steel in sulphuric acid solutions

Corrosion of mild steel (MS) in industries has become a menace that has led to the use of organic green inhibitors from plant origin, which is seen as a cheap, eco-friendly substitute for inorganic inhibitors. This work employed Solanum macrocarpon (SM) methanol leaf extract as a green inhibitor using a gravimetric method at 303-323 K, respectively. The phytochemical screening was done using standard methods to identify the phytochemical compounds in the leave extract. The Fourier transform infrared (FTIR) analysis was also done to elucidate the functional groups that contain heteroatoms responsible for the inhibition efficiency. The effectiveness of the inhibition efficiency increased with concentration and decreased with rising temperature. The results demonstrated that Solanum macrocarpon leaf methanol extract is an effective mild steel corrosion inhibitor in 0.5 M H2SO4. 95% optimum inhibition efficiency (I.E) was observed at 0.5% w/v concentration for 303 K. The inhibition potential was attributed to the phytochemical compounds in the leaf extract, which contain polar functional groups and hetero-atoms in their structures. The E-a and Delta G(ads) showed that the adsorption mechanism followed physisorption. The results showed the potential use of SM methanol extract as a corrosion inhibitor in mild steel, which can decrease corrosion in industries. Article Highlights center dot Solanum macrocarpon methanol leaf extract contains phytochemical constituents containing functional groups with heteroatoms responsible for inhibitory properties.center dot Increasing the concentration of the extract from 0.1 to 0.5%w/v reduces the corrosion rate of the mild steel from 303-323 K in the acidic medium.center dot Solanum macrocarpon methanol leaves extract a potential green organic inhibitor to be used in industries to reduce acid corrosion of mild steel.