Experimental, DFT calculations and MC simulations concept of novel quinazolinone derivatives as corrosion inhibitor for mild steel in 1.0 M HCl medium

Abstract New compounds derived from quinazolinone namely, 3-methyl-2-(p-tolyl) quinazolin-4(3H)-one (QZ-CH3), 2-(4-hydroxyphenyl)-3-methylquinazolin-4(3H)-one (QZ-OH), 3-methyl-2-(4-nitrophenyl) quinazolin-4(3H)-one (QZ-NO2) and 3-methyl-2-phenylquinazolin-4(3H)-one (QZ-H) were synthesized and characterized by RMN spectroscopy. Their inhibition efficiencies against mild steel corrosion in 1.0 M HCl at 298 K were investigated by using electrochemical methods, surface analysis and UV–visible spectrometry coupled with DFT calculations and Monte Carlo (MC) simulation. It is seen that these four products are good corrosion inhibitors for mild steel in 1.0 M HCl, where their inhibition efficiencies increase with concentration to reach maximum values of 92%, 96%, 82%, and 81% at 10−3 M of QZ-OH, QZ-CH3, QZ-NO2 and QZ-H, respectively. In addition, the influence of the temperature solution ranges from 298 K to 328 K, on the performance of the quinazolinone derivatives indicated that it decreases with temperature solution. The activation and thermodynamic parameters indicated that these products act via chemical adsorption on the metallic surface. This finding was confirmed by surface analysis and UV–visible spectrometry with the formation of a thick protective layer on mild steel surface and the formation inhibitor-complex in solution, respectively. Indeed, it is found that these quinazolinone derivatives adsorb on mild steel surface according to Langmuir adsorption isotherm. Finally, the DFT and MC simulation studies don't correlate with electrochemical measurements and surface analysis.