Electrochemical and Theoretical Study of Metronidazole Drug as Inhibitor for Copper Corrosion in Hydrochloric Acid Solution

摘要

The approach current trend of expired drugs as corrosion inhibitors for metals and alloys in differentenvironments to avoid its pollution with corrosion products by diminishing the degradation rate ofmaterials is reflected, in our study, by investigation of metronidazole (MNZ) antibiotic andantiprotozal drug, as corrosion inhibitor for copper in hydrochloric acid solution. The electrochemicalmeasurements associated with UV-Vis spectrophotometry followed by quantum chemical calculationswere performed, their results showing that: MNZ inhibition efficiency reached a value of 90.0 % 2, at-11.0 mmol L inhibitor concentration; the amount of corrosion products decreases in the presence ofMNZ; the formation of complexes between MNZ and copper, as well as their effective contribution togrowth a protective layer at the metal/solution interface; MNZ action mechanism resulted from theparallel processes between the occurrence of chemical bonds and electrostatic interactions wascertified by quantum chemical calculations, when ab initio to the approximate level of densityfunctional theory (DFT) was used by assigning the Gamees molecular modeling.