Multi-method evaluation of a 2-(1,3,4-thiadiazole-2-yl)pyrrolidine corrosion inhibitor for mild steel in HCl: combining gravimetric, electrochemical, and DFT approaches

Abstract

The corrosion inhibition properties of 2-(1,3,4-thiadiazole-2-yl)pyrrolidine (2-TP) on mild steel in a 1 M HCl solution were investigated using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP) measurements. In addition, DFT calculations were performed on 2-TP. The polarization curves revealed that 2-TP is a mixed-type inhibitor. The results indicate that 2-TP is an effective inhibitor for mild steel corrosion in a 1.0 M HCl solution, with an inhibition efficiency of 94.6% at 0.5 mM 2-TP. The study also examined the impact of temperature, revealing that the inhibition efficiency increases with an increasing concentration of 2-TP and decreases with a rise in temperature. The adsorption of the inhibitor on the mild steel surface followed the Langmuir adsorption isotherm, and the free energy value indicated that the adsorption of 2-TP is a spontaneous process that involves both physical and chemical adsorption mechanisms. The DFT calculations showed that the adsorption of 2-TP on the mild steel surface is mainly through the interaction of the lone pair of electrons on the nitrogen atom of the thiadiazole ring with the metal surface. The results obtained from the weight loss, potentiodynamic polarization, EIS and OCP measurements were in good agreement with each other and confirmed the effectiveness of 2-TP as a corrosion inhibitor for mild steel in 1.0 M HCl solution. Overall, the study demonstrates the potential use of 2-TP as a corrosion inhibitor in acid environments.

Unraveling the corrosion inhibition behavior of prinivil drug on mild steel in 1M HCl corrosive solution: insights from density functional theory, molecular dynamics, and experimental approaches

“…Table 3 deliberates an overview of the corrosion mitigation effectiveness of mild steel in a highly corrosive 1 M HCl solution when subjected to varying concentrations of inhibitor (50–500 ppm) at 298 K. The inclusion of electrochemical parameters such as the constant phase element (CPE.Yo), exponent (n), solution resistance (R s ), polarization resistance (R p ), and charge transfer resistance (R ct ) provide insightful information about the inhibitor’s inhibition effectiveness and corrosion behavior. The results presented in Table 3 indicate a clear trend towards increased inhibition efficiency with higher concentrations of the inhibitor ( Al-Amiery et al, 2023 ; Yadav et al, 2023b ; Narang et al, 2023 ). For instance, at 50 ppm concentration, the, I.E., % is recorded at 61.37%, demonstrating a substantial lessen in the C R compared to the uninhibited condition.…”