Electrochemical and Computational Studies for Mild Steel Corrosion Inhibition by Benzaldehydethiosemicarbazone in Acidic Medium

Abstract

The inhibiting effect of benzaldehydethiosemicarbazone (BTSC) on the mild steel alloy corrosion in a 1 M sulfuric acidic solution was potentiostatically investigated at four temperatures, in the range of 298.15 to 328.15 K. Three BTSC concentrations, ranging from 100 to 300 mg/L, were tested. Mild steel corrosion feasibility decreases with increasing inhibitor concentrations, and also with the rise in temperature. A protection efficiency of 96% was obtained at 300 mg/L, and 328.15 K. Potentiostatic polarization studies showed that BTSC acted as a mixed type inhibitor. The main kinetic effect of the BTSC inhibitor added to the sulfuric acid solution was to considerably enhance activation energy values, pre-exponential factor and activation entropy of the alloy corrosion. This was because BTSC shifted the corrosion reaction on the mild steel surface to reaction sites where energy was relatively higher than that on which the corrosion occurred in the inhibitor absence. The inhibitor adsorption followed the Langmuir adsorption isotherm. The activation thermodynamic functions (Ea, Kads, ΔGads., ∆Hads. and ∆Sads) were evaluated. The obtained activated parameters revealed that BTSC adsorption took place through chemisorption. Scanning electron microscopy (SEM) technique was used to provide insight into the formation of a protective film on the alloy surface. To provide a relationship between the BTSC's molecular structure and its corrosion inhibition capability, quantum chemical studies were achieved using density functional theory (DFT) at the B3LYP/6-311G level.

Corrosion Inhibition Efficiency Investigation of Yttrium Oxide Nanoparticles Coated on Carbon Steel Alloy

“…3 From Fig. 2, it is observed that the relationship between corrosion rate and temperature is linear , and the corrosion rate decrease when the concentration of the inhibitor is 0.15N and 0.26N , but the corrosion rate increased at 0.37N to be close to the corrosion rate of blank , as mentioned previously due to agglomeration in yttrium oxide nanoparticles, the nature of the bonding of molecules to the metal surface is physical adsorption 23,27 . The negative values of ΔS* reveal that the activated complex in the rate determining step represents association rather than the dissociation step, this means a decrease in disorder take place 28 .…”

“…It has been observed that the rate of corrosion increased with increasing the temperature because temperature accelerates corrosion process such as electrochemical reaction, chemical reaction, and the process of transferring of reactive species to the metal surface 23 .…”

Study the Inhibition Effect of Amoxicillin Drug for Corrosion of Carbon Steel in Saline Media

“…Higher values of activation energy (E a ) in the presence of inhibitor refer to a strong inhibitive action by increasing energy barrier for the corrosion process 12 . On the other hand, a decrease of the corrosion activation energy with an increase of inhibitor concentrations, is associated with an increase in inhibition efficiency with increasing temperature as shown in Table 3, referring to the formation of an adsorption layer of chemical nature, which involves the transfer of electrons from amoxicillin molecules to the steel surface, results to the formation of coordinate bond with the surface of carbon steel 13,14 . Alternatively, a chemisorption mechanism associated with increase in inhibition efficiency with temperature and higher activation energy in the presence of the inhibitor [15][16][17] .…”

Propriedades químico-quânticas utilizando o método TFD: uma ferramenta teórica aplicada no estudo de inibidores de corrosão

“…Assim, o método da TFD tem sido amplamente utilizado para analisar as estruturas eletrônicas de inibidores e o tipo de adsorção usando uma série de descritores quânticos que fornecem informações importantes sobre os mecanismos de inibição de corrosão e corroborar com dados experimentais (Chen et al, 2018;Ganash, 2018;Masoud et al, 2010;Quattrociocchi et al, 2020;Salman et al, 2019;Swetha et al, 2019).…”