Corrosion‐Resistant and Photocatalytic PVDF‐ETFE‐ZrO₂ Superhydrophobic Composite Coating

ABSTRACT In this study, superhydrophobic PVDF‐ETFE‐ZrO 2 composite coatings were prepared on carbon steel surfaces using a two‐step spraying method. When the content of modified ZrO 2 particles was 20 wt% and the particle size was 100 nm, the coating showed a micro‐ and nano‐graded rough structure with a water contact angle of 162.5°. The coating exhibited excellent corrosion resistance with a low corrosion current density of 2.918 × 10 ‐7 A/cm 2 , which was two orders of magnitude lower than that of the Q345 steel substrate, and a protection efficiency of 98.22%. It remained superhydrophobic after 120 h of immersion in 3.5 wt.% NaCl solution and maintained a contact angle > 150° in the pH=2 ~ 13 range. In addition, the coating showed excellent mechanical stability with a contact angle of > 150° after 200 cm of sandpaper abrasion and a contact angle of 151.2° after 45 tape stripping cycles. The coating is both self‐cleaning and photocatalytic, with a degradation rate of 30.24% for rhodamine B in 3 h and 21.78% after six cycles. This method provides an efficient solution for the large‐scale preparation of high‐performance superhydrophobic surfaces.