Achieving hierarchical structure with superhydrophobicity and enhanced anti-corrosion via electrochemical etching and chemical vapor deposition

In this work, superhydrophobic surfaces with hierarchical and multi-scale micro/nanostructures were fabricated by a simple method without damaging the substrate material. Electrochemical etching and chemical vapor deposition were taken to adhere the robust electroplated Ni with the excellent hydrophobic material of polydimethylsiloxane (PDMS) to provide a double-layer protection for the bare Cu substrate. The as-prepared superhydrophobic surface exhibited a high contact angle (CA) of 158.5 ± 0.4° and a low slide angle (SA) of 2.1 ± 0.2°. Electrochemical corrosion test results showed the corrosion current density of superhydrophobic surface was about 4 orders of magnitude lower than that of bare Cu in 3.5 wt% NaCl solution, indicating that the superhydrophobic surface had superior corrosion resistance. We also discussed the corrosion resistance mechanism of superhydrophobic surface with hierarchical and multi-scale micro/nanostructure. In addition, the as-prepared superhydrophobic surface also demonstrated good mechanochemical and self-cleaning properties, which may greatly facilitate the application in practical conditions.