Synthesis, characterization, and corrosion inhibition performance of multifunctional organoselenium schiff base–metal hybrids for Q235 steel in acidic media

In this study, we report the synthesis of a novel selenated Schiff base, namely, 2-(((4-(methylselanyl)phenyl)imino)methyl)phenol (MeSeOH), and its [Ni(MeSeO) 2 (H 2 O) 2 ] complex. Their corrosion inhibition performance toward Q235 steel in 0.5 M H 2 SO 4 was evaluated using electrochemical techniques, surface characterization, density functional theory (DFT) calculations, and Monte Carlo (MC) simulations. The Ni(II) complex [Ni(MeSeO) 2 (H 2 O) 2 ] exhibited a maximum inhibition efficiency of 95.5%, markedly higher than that of the free ligand MeSeOH. DFT analysis and MC simulations indicate strong adsorption of the inhibitors on the steel surface and a favorable planar orientation that maximizes surface coverage. These results demonstrate that the synthesized organoselenium Schiff base and its Ni(II) chelate are promising candidates for anticorrosion applications, particularly as protective coatings in oil and gas, automotive, and construction industries.