Highly anticorrosion, self-cleaning superhydrophobic Ni–Co surface fabricated on AZ91D magnesium alloy

A highly anticorrosion and self-cleaning superhydrophobic surface with hierarchical flowerlike structures fabricated on AZ91D magnesium alloy is reported in this work. The hierarchical micro/nanostructures were created through electrodeposition of Ni–Co alloy coating. Followed by modification of stearic acid, a superhydrophobic surface with a water contact angle as high as 167.3   ±   1.3° and an ultra-low sliding angle of about 1° was achieved. The anticorrosion performance of the superhydrophobic surface was studied by using a combination of potentiodynamic polarization and EIS in neutral 3.5   wt.% NaCl solutions. The superhydrophobic surface can present an excellent anticorrosion effect with the inhibition efficiency of 99.99% to the bare magnesium alloy and its corrosion rate being 0.06% of that of bare magnesium alloy. The resulting superhydrophobic surface showed excellent superhydrophobicity in a wide range of pH values from 1 to 14. Besides, the as-prepared superhydrophobic surface possessed good chemical stability and self-cleaning effect. It's believed that the highly anticorrosion and self-cleaning superhydrophobic surface can efficiently protect magnesium alloy from corrosion and expand its application scope.