Tailoring the Micro-galvanic Dissolution Behavior and Antifouling Performance Through Laminated-Structured Cu-X Composite Coating

Marine biofouling is a ubiquitous and serious problem in maritime engineering. Here, we reported an effective antifouling approach through facile fabrication of laminated-structured Cu-X composite coatings by plasma spraying of mechanically blended Cu and X powders, in which X is a type of metal nobler than Cu. The Cu-X coatings were designed to controlled release Cu ions from Cu/X micro-galvanic cells and thus to achieve long-term and effective antifouling performance. The effect of cathode X composition (i.e., Ni, stainless steel (SS), and Ti) on the micro-galvanic dissolution behavior and antifouling performance of the Cu-X coatings was systematically investigated. Results indicated that the cathode X composition exhibited little influence on the micro-galvanic dissolution mechanism of Cu-X coatings. Nevertheless, Cu ions release rate increased as follows: Cu-Ni coating < Cu-SS coating < Cu-Ti coating. Moreover, the Cu-X composite coatings exhibited long-lasting antifouling capability and remarkable antifouling efficiency of ~100%. Electrochemical test results revealed that the potential difference between Cu/X was the primary factor determining the difference of Cu dissolution rate and thus the Cu ions release rate between different Cu-X coatings. These results would open a new window for designing long-term and environment-friendly Cu-X antifouling coatings by employing various tunable bimetals.