4-(1H-benzo[d]imidazol-3-ium-2-yl)pyridine 1-oxide dihydrogen phosphate hydrate as a corrosion inhibitor for carbon steel in 1.0M HCl: Experimental and theoretical studies

초록

This study reports the synthesis and structural characterization of the organic-inorganic hybrid material 4-(1H-benzo[d]imidazol-3-ium-2-yl)pyridine 1-oxide dihydrogen phosphate hydrate (BIPyOH), with a focus on its corrosion inhibition properties. The structure of the crystal is based on the structure of an organic cation and that of the dihydrogen phosphate anion and the molecules of water. There are O-H & sdot;& sdot;& sdot;O, N-H & sdot;& sdot;& sdot;O and O-H & sdot;& sdot;& sdot;N interactions that create a stable three-dimensional network of hydrogen bonding. Such interactions help to hold the crystal structure together and to give it its packing. The optical parameters of BIPyOH were also studied. The material has high absorption in the ultraviolet region and high transparency in the visible region. Further analysis of the electronic structure was performed using electron density, electron localization function (ELF) and localized orbital locator (LOL) analysis. BIPyOH shows excellent corrosion inhibition properties towards carbon steel in 1.0 M HCl, where inhibition efficiency is around 90% at low concentrations. Electrochemical results show that BIPyOH is a mixed-type inhibitor. It has an inhibition mechanism that is principally related to spontaneous adsorption onto the surface of the carbon steel and follows the Langmuir adsorption isotherm. Monte Carlo simulations also show that the BIPyO cation is stable on the Fe surface, both physisorbed and chemisorbed. The results presented here show that BIPyOH is a potential organic-inorganic hybrid inhibitor for the corrosion of carbon steel in an acidic environment.

키워드