Preparation of Ni-Cu-based superhydrophobic composite coatings with anti-corrosion and self-cleaning properties

Inspired by biological surfaces such as lotus leaves and Stenocara beetles, superhydrophobic coatings have attracted considerable attention due to their exceptional water repellency, self-cleaning behavior, and corrosion resistance. In this work, Ni-Cu/HDTMS-MX superhydrophobic coatings were fabricated through the co-deposition of MXene with a Ni Cu coating, followed by surface modification using hexadecyltrimethoxysilane (HDTMS). The Ni-Cu/HDTMS-MX coatings exhibit excellent superhydrophobic performance, with a water contact angle (CA) of 155.1 ± 2.2° and a roll-off angle (RA) of 6 ± 0.5°, accompanied by effective water jet rebound, self-cleaning capability, and enhanced corrosion resistance. Electrochemical measurements demonstrate an order-of-magnitude reduction in corrosion rate (0.5 × 10 −3  mm·y −1 ) and corrosion current density (0.4 × 10 −7 A·cm −2 ), while the impedance modulus |Z| at 0.01 Hz for the Ni-Cu/HDTMS-MX coating reaches approximately 375% of that of the Ni Cu coating. The improved corrosion resistance is attributed to the labyrinth-like diffusion barrier introduced by MXene and the HDTMS-derived hydrophobic film, which significantly lowers the surface energy of the coating. Upon contact with aqueous media, the coating maintains a Cassie-Baxter wetting state, indicating stable superhydrophobic behavior. The entrapped air pockets within the hierarchical micro/nanostructure effectively block the penetration of corrosive species, thereby improving corrosion resistance in chloride-containing environments. This work provides a feasible strategy for designing durable superhydrophobic coatings for the long-term protection of carbon steel in harsh marine environments.