A Facile Preparation Method for Corrosion-Resistant Copper Superhydrophobic Surfaces with Ordered Microstructures by Etching

Superhydrophobic surfaces wit ordered hierarchical microstructures were prepared on copper substrates by combining thermal transfer and etching. The surface morphology, wettability, chemical composition and corrosion resistance were, respectively, characterized via scanning electron microscopy, a three-dimensional confocal microscope, contact angle measurement, X-ray diffraction, X-ray photoelectron spectroscopy, electrokinetic polarization and electrochemical impedance spectroscopy techniques. The contact angle of the obtained superhydrophobic surface is up to 153.3° with a reduction in the corrosion current density from 3.9105 × 10−5 A/cm2 to 3.5421 × 10−6 A/cm2 via the electrokinetic polarization curve test, and the maximum capacitive arc radius of the superhydrophobic surface is about 2.5 × 104 Ω cm2 via the electrochemical impedance spectroscopy test, which is two orders of magnitude higher than that of bare copper substrate, and the maximum modulus value |Z| is also two orders of magnitude higher than that of bare copper substrate, indicating that the superhydrophobic surface has better corrosion resistance. This method provides an effective etching approach toward preparing superhydrophobic surfaces with ordered microstructures.