(3,5-dimethyl-1H-pyrazol-1-y1) (4-((3,4-dimethoxybenzylidene) amino) phenyl) methanone as a novel corrosion inhibitor for low-carbon steel in hydrochloric acid: Synthesis, diagnosis, and application

•Novel DPMM inhibitor is synthesis and confirmed with FTIR.•DPMM showed high ability to inhibit steel corrosion reaction as a mixed type inhibitor.•The adsorption isotherm of DPMM obeyed Longmuir adsorption isotherm. A novel organic corrosion inhibitor, named (3,5-dimethyl-1H-pyrazol-1-y1) (4-((3,4-dimethoxybenzylidene) amino) phenyl) methanone (DPMM) has been effectively synthesized and characterized. FTIR and NMR have been used to diagnose DPMM's functional groups and components. Electrochemical and weight loss methods were used to assess the inhibitor efficacy for low-carbon steel in 1 M HCl. By raising the temperature and DPMM concentrations, the inhibition efficiency improved. The inhibition efficiency approached 95.5 % at 400 ppm of DPMM and 60 °C. The efficiency of the inhibitor was ascribed to the formation of a protective mono-layer on the steel surface. The mechanism of the adsorption process was examined using the Langmuir adsorption isotherm, whereas the mechanism of inhibition was examined using theoretical quantum chemical simulations. The results revealed that the DPMM was the donor of electron, while the steel surface was an electron acceptor.