Layer-by-layer stacked graphene nanocoatings by Marangoni self-assembly for corrosion protection of stainless steel

Graphene nanosheets are widely used in anti-corrosion polymeric coating as filler, owing to the excellent electrochemical inertness and barrier property. However, as the arrangement of graphene nanosheets is difficult to form a perfect layered structure, polymeric coating with graphene nanosheets usually needs micron-scale thickness to ensure the enhancement of corrosion protection. In this work, layer-by-layer stacked graphene nanocoatings were fabricated on stainless steel by self-assembly based on Marangoni effect. The anti-corrosion property of graphene coatings were studied through Tafel polarization curves, electrochemical impedance spectroscopy and accelerated corrosion test with extra applied voltage. The self corrosion current density of optimized three-layered graphene coated sample was one quarter of that of bare stainless steel. And the self corrosion potential of optimized sample is increased to -0.045 V. According to the results, graphene nanocoatings composed of layered nanosheets exhibits good anti-corrosion property. Besides, the self-assembly method provide a promising approach to make layered-structure coating for other researches about 2D material nanosheets. (C) 2020 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

Graphene nanosheets are widely used in anti-corrosion polymeric coating as filler due to their excellent electrochemical inertness and barrier property. However, the difficulty in forming a perfect layered structure leads to the need for micron-scale thickness in polymeric coatings with graphene nanosheets. In this study, layer-by-layer stacked graphene nanocoatings were fabricated on stainless steel using a self-assembly method based on the Marangoni effect. The anti-corrosion properties of the graphene coatings were evaluated, with the optimized three-layered graphene-coated sample showing significantly lower self-corrosion current density compared to bare stainless steel.