Fabrication of a Robust Superhydrophobic Ni Coating with Micro–Nano Dual‐Scale Structures on 316L Stainless Steel

Herein, a superhydrophobic Ni coating is prepared on 316L stainless steel by electrodeposition and low energy modification with tetradecanoic acid. After 20 min of electrodeposition with a current density of 8 A dm−2, a Ni coating with micro–nano dual‐scale structures is obtained. The coating becomes superhydrophobic with a water contact angle (WCA) of 160.4° and a sliding angle (SA) of 8.3° after being immersed in the tetradecanoic acid solution (5 g L−1, 12 h). A two‐level structure model is established for explaining the effect of morphology on the wettability of the coating. The WCA value of the superhydrophobic Ni coating retains above 150° after being exposed in outdoor environment for 6 months and in flowing environment for 7 days. In addition, the coating still shows superhydrophobicity after 9 times of mechanical abrasion test, 12 h of acid soaking (pH = 1), and 16 h of heat treatment in 200 °C. Moreover, the coating improves the corrosion resistance of the steel substrate. This superhydrophobic Ni coating provides a simple method to prevent stainless steel from corrosion. And the theoretical calculation of the two‐level model can provide an innovative strategy for designing the structure of the superhydrophobic coating. A superhydrophobic Ni coating with special micro‐nano dual‐scale structures is successfully prepared on 316 L stainless steel. A two‐level structure model is established for explaining the effect of morphology on the wettability of the coating. The superhydrophobic coating has extremely low adhesion, water repellency, excellent acid resistance, and stability, etc.