LAUSR

Four hydrosoluble macroazacyclic compounds, phosphorus phthalocyanine and substituent phosphorus triaza tetrabenzo corrole substituted with amino or sulfonate groups respectively, were investigated as corrosion inhibitors for mild steel in 1 mol/L HCl. The results obtained from weight loss test showed that the inhibitive efficiency of phosphorus phthalocyanine was higher than the phosphorus triaza tetrabenzo corrole; while the amino substituent phosphorus phthalocyanine showed the strongest inhibitive ability among them. The potentiodynamic tests illustrated that these inhibitors protected steel according to the mixed type mechanism on electrochemistry; while the impedance spectra revealed the increasing of charge transfer resistance and the decreasing of double layer capacitor caused by the adsorption of inhibitors. The surface analysis (XPS and SEM) proved the protection of steel surface by the adsorbed inhibitors. The molecular dynamic simulation indicated the advantages of phosphorus phthalocyanine as inhibitors associating with highly binding stability and stable adsorption configuration. The unique degradation properties of these inhibitors under visible light made them useful with environmental advantage in application.