Newly synthesized triazolopyrimidine derivative as an inhibitor for mild steel corrosion in HCl medium: an experimental and in silico study

A new triazolopyrimidine derivative, namely, 6-hydroxy-7-phenyl-6,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidin-5(4H)-one (HPTP) was synthesized. Its corrosion inhibition performance on mild steel in 1M HCl solution was researched through weight loss, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) approaches. The experimental results show that the inhibition efficiency of HPTP increases with the increase of concentrations, whereas decreases as the temperature rises. PDP data reveal that the HPTP acts as a mixed type inhibitor. EIS results imply that the HPTP molecules form an antiseptic layer at the steel/solution interface. The adsorption of the inhibitor molecules on the steel surface follows Langmuir's adsorption isotherm. In addition, density functional theory (DFT) calculations were also employed to gain further insight into the adsorption behavior and inhibition mechanism.