Study of antiviral drug Famciclovir as a corrosion inhibitor for carbon steel in hydrochloric acid medium

A nucleoside antiviral drug namely 2-[2-(2-Amino-9H-purine-9-yl)ethyl]-1,3-propanediol Diacetate (Famciclovir, or FAM for short), is developed as a corrosion inhibitor of carbon steel in hydrochloric acid medium. The corrosion inhibition performance is explored using electrochemical measurement and detailed surface characterization techniques. The results indicate that the charge transfer resistance (Rct) values of carbon steel samples modified with FAM get a significant improvement, and the highest corrosion inhibition efficiency reached 96.87% at a concentration of 1.0 mM after soaking for 2 h at 298 K. When the solution temperature rises from 298 K to 318 K, the efficiency of the corrosion inhibitor with a concentration of 1.0 mM slightly decreases from 96.87% to 93.92% after soaking for 2 h. FAM presents a mixed corrosion inhibitor that simultaneously inhibits the anodic oxidation and cathodic reduction processes of carbon steel electrodes in hydrochloric acid medium. Adsorption of FAM on the surface of carbon steel is found to follow the Langmuir adsorption isotherm and it is mainly chemical adsorption. Confocal micrograph, X-ray diffraction analyzer (XRD) and X-ray photoelectron spectrometer (XPS) results further validate that FAM can adsorb on carbon steel surface, which inhibits the corrosion of HCl.