Inhibitory action of camellia sinensis extract on the corrosion of carbon steel in 0.1 mol L-1 HCl

Abstract

The effect of Camellia sinensis extracts on the corrosion of carbon steel in 1 mol L-1 HCl was examined. Polarization curves show that this extract act as mixed-type inhibitor with predominantly cathodic characteristic. The inhibition efficiency obtained from the polarization curves and electrochemical impedance increases with the extract concentration, with 89 % in the presence of 1500 ppm of the extract. The apparent activation energy (Ea) for the dissolution of C-steel slightly increased when the extract was used. This result could be attributed to the physisorption of the inhibitor on the steel surface.