Corrosion mitigation of mild steel in hydrochloric acidic medium using new synthesized 1,3,5-triphenyl-pyrazole bearing two methoxy groups: Experimental and computational investigations

A new pyrazole derivative was synthesized and tested against mild steel corrosion in a 1 M HCl solution. The anticorrosion performance of the compound was studied by means of electrochemical measurements; weight loss analysis and scanning electron microscopy, with special attention to inhibitor concentration and temperature in operation. The novelty of the present work is the synthesis of a 1,3,5-triphenylpyrazole with two methoxy groups and its cooperative electronic effect was studied for the first time by both experimental and theoretical (DFT, Monte Carlo as well as molecular dynamics) combined approach. The efficiency of inhibition increased with concentration and was 98 % at 1 × 10⁻³ M. The inhibition mechanism was described as mixed-type based upon potentiodynamic polarization measurements, and it was concluded that a protective adsorbed film emerged. The adsorption studies showed that the inhibitor could follow the Langmuir isotherm model, which had chemisorption and physisorption components. Computational analyses supported these findings, confirming strong adsorption interactions between the inhibitor and the metal surface. Altogether, the results demonstrate that this newly synthesized pyrazole derivative is a highly effective and promising corrosion inhibitor for industrial applications. Calculations confirmed these data indicating that there was a hard adsorption of the inhibitor on the metal surface. Overall, the findings proved this newly prepared pyrazole derivative to be an excellent and promising industrial corrosion inhibitor.