Synthesis, structural analysis, and inhibition approach of novel eco-friendly chalcone derivatives on API X65 steel corrosion in acidic media assessment with DFT & MD studies

Abstract

This work aims to prepare two chalcone derivatives and explore their corrosion inhibition for API steel in 0.5 M sulfuric acid. Different analysis was used to elucidate their chemical structures. Gravimetrical, morphological, and electrochemical techniques were used to explore their inhibition influences. The experimental data discovered that the average inhibition efficiencies of IPC and IOPC at 10 −3 M were 94.4% and 95.5%, respectively. The potentiodynamic polarization results discovered that the two indole derivatives perform as mixed inhibitors. The calculated thermodynamic parameters obvious that the IPC and IOPC obey the Langmuir adsorption isotherm model. The adsorption free energies of ( Δ G a d s o ) values were found –39.1 to –40.9 kJ mol −1 for IPC & IOPC, respectively. The SEM/EDS morphological inspection was found compatible with the experimental measurements. Theoretical and molecular dynamic simulation studies were applied to elucidate the effect of the chemical structure of IPC and IOPC on their inhibition efficiencies, and further to clarify their adsorption process on the carbon steel substrate. The obtained experimental results were in line with the calculated theoretical parameters. • Chalcone derivatives exhibit high inhibition efficiency. • The two inhibitors acted as mixed-type inhibitors. • The inhibition occurs via physical and chemical adsorption. • The inhibitors obeyed Langmuir adsorption isotherm. • Theoretical calculations agree with the experimental results.