Biologically active 1-(1-Phenyl-1H-[1,2,3]triazol-4-yl)-ethan-1-one as a potent carbon steel protector from acidic environment and its synergistic effect with cerium salt

This work investigates the corrosion inhibition behavior of the bioactive compound 1- (1-Phenyl-1H-[1,2,3]triazol-4-yl)-ethan-1-one (PTE) on carbon steel (CS) in HCl medium. . 1H NMR and 13C NMR confirmed the structure of PTE. The inhibition performance was evaluated using gravimetric, electrochemical, and surface analytical techniques. The results demonstrate that inhibition efficiency increases with inhibitor concentration and decreases with rising temperature. Thermodynamic and adsorption studies reveal that PTE adsorbs spontaneously on the carbon steel surface, following the Langmuir adsorption isotherm. Electrochemical measurements indicate that PTE functions as a mixed-type inhibitor. Surface characterization by SEM–EDAX and AFM confirms the formation of a protective inhibitor film on the steel surface. Density functional theory calculations support the experimental observations by elucidating the electronic properties responsible for adsorption. Furthermore, the presence of CeCl₃ exhibits a synergistic effect, significantly enhancing corrosion protection at low PTE concentration. The antimicrobial activity of PTE was also confirmed using the disc diffusion method, highlighting its multifunctional potential.