Fabrication of organic-inorganic hybrid materials on metal surface for optimizing electrochemical performance

Abstract

Surface chemistry is a significant field of research, especially for the preparation of organic-inorganic hybrid materials in which nearly every atom is anchored at the interface. Herein we report on the functional binding agents (FBAs), Mg(OH)2 or Co(OH)2–Mg(OH)2–Co(OH)(NO3), as efficient tools for functionalising surfaces, whereby the morphology and growth of the organic-inorganic coating can be varied by varying the interfacial composition to achieve improved functionality. To demonstrate the potential of this strategy, we combine plasma electrolytic oxidation (PEO) and a two-step dip chemical coating (DCC) technique to deliver multi-layered constructions of several chemical compositions comprising inorganic and organic components. A novel single layer of FBAs is fabricated on the rough inorganic coating through chemical treatment via DCC, transforming it into a binding site for primary clusters of 2-mercaptobenzimidazole (MBI) molecules. Thus, FBAs form coordination complexes with organic molecules, which grow on FBA surfaces. Finally, electrochemical measurements reveal that the self-assembly of organic-inorganic hybrid heterostructures appreciably suppresses metal oxidation and oxygen reduction, due to a synergistic effect arising from the combination of FBAs with organic and inorganic coatings.