Enhanced inhibition of steel corrosion by L-cysteine under visible-light illumination

The heteroatoms such as nitrogen, oxygen, and sulfur of organic inhibitor play a crucial role on its corrosion inhibition behavior. In order to reveal their adsorption behavior and inhibition performance under illumination condition on steel surface, this study selects L-cysteine as study object. On the basis of electrochemical measurement, surface analysis, and theoretical calculation, a promising increase in corrosion inhibition efficiency is observed when visible-light is impinged on steel surface in sodium chloride solution with L-cysteine. The enhanced performance is attributed to the sample surface photovoltaic effect, thereby facilitating both the thiol and the amino groups to tilt toward the surface.