Surface functionalization of XC18 steel using a new transition metal complex for remarkable corrosion performance: Empirical and theoretical studies

Synthesis of transition metal complexes (TMC) having specific characteristics is advantageous for combining their organic and inorganic properties, to help prevent metals from corrosion. In this study, the corrosion inhibition behavior of [N, N′-bis(salicylidene)-2,2-dimethyl-1,3-propanediaminato] copper (II) (CuL) on the surface of XC18 steel surface immersed in 1.0 M HCl was investigated. The thermodynamic and kinetic corrosion parameters were determined using the mass loss (ML) and electrochemical measurement methods. CuL exhibited a good corrosion inhibition efficiency of 96.72 %. The adsorption behavior of CuL followed the Langmuir isotherm model, indicating both physical and chemical interactions. Morphological structural analysis demonstrated that CuL formed a protective film between the surface of XC18 steel and the corrosives elements, thus confirming its adsorption onto XC18 steel surface. Theoretical calculations were consistent with the experimental findings, thereby confirming that the adsorption of CuL onto the steel surface comprises both physisorption and chemisorption processes. These calculations elucidate the specific bonding nature and emphasize the significant inter- and intra-molecular interactions that enhance the stability and adsorption capability of the CuL inhibitor. The successful formation of a protective layer on the surface of XC18 steel using a TMC signifies exciting prospects for the development of advanced materials with diverse applications.