Stearic acid-coated superhydrophobic Fe2O3/Fe3O4 composite film on N80 steel for corrosion protection

Abstract

Fe2O3/Fe3O4 composite films with micro-nanostructure are prepared on the N80 steel surface by a two-step hydrothermal method, followed by heat treatment. The prepared dual-scale film, after the modification with stearic acid, shows superhydrophobic property with a water contact angle of 159.6° and sliding angle of 2.2°. The greatly decreased corrosion current density and the largely increased impedance indicate the superhydrophobic surface can protect steel sample well from corrosion. Furthermore, the superhydrophobic Fe2O3/Fe3O4 composite film also showed excellent self-cleaning ability and was able to maintain its anti-wettability when immersed in water. Our work finds that the concentration of NaOH in the second hydrothermal method is a critical factor for the morphology of the Fe2O3 film and the annealing treatment plays a significant role in realizing the superhydrophobic stearic acid coated micro-nanostructure Fe2O3/Fe3O4 composite.