Rational designed structured superhydrophobic iron oxide surface towards sustainable anti-corrosion and self-cleaning

A hierarchical micro-/nanostructure, consisting of nano-sized Fe2O3 needles vertically grown on the {111} facets of micro-octahedral Fe3O4 particles, has been successfully prepared on the surface of N80 steel using hydrothermal treatment followed by annealing. The nanoneedles were transformed from nanoparticles on the micro-octahedral facets under the influence of mixed acetone and acetic acid gas atmosphere, and the length of nanoneedles can be controlled by the annealing time. The superhydrophobic Fe2O3/Fe3O4 composite surface with water contact angle (WCA) of 157.3? and sliding angle (SA) of 8.1? was obtained after decorated with stearic acid. The influence of the annealing time on the surface morphology and hydrophobicity was explored and optimized. The superhydrophobic surface displays great self-cleaning and anti-corrosion performances with good mechanical robustness. This method opens a new venue towards preparing micro-nanostructures on the surface of metallic materials for enhanced anti-corrosion and self-cleaning applications.