Capsules containing corrosion inhibitors have drawn considerable attention in the field of self-healing corrosion protection because of their appropriate size and high efficiency. ZnO has become a type of promising encapsulants due to its high structural tunability and unique surface chemical property. Meanwhile, carbon dots (CDs) have huge application potential to replace the existing toxic corrosion inhibitors. Herein, a corrosion-resistant microcapsule with nitrogen-doped carbon dots (NCDs) as the core material and ZnO as the wall material (NCD@ZnO MCs) was developed to exert perfectly the advantages of the two materials. The NCDs were first synthesized by solvothermal method, and the NCD@ZnO MCs were then fabricated just by stirring at room temperature. The morphology, microstructure and composition of NCDs and NCD@ZnO MCs were characterized, respectively. The superiority of NCD@ZnO MCs in improving the anti-corrosion resistance of waterborne coatings was also discussed. The results showed that the obtained NCDs had a size distribution of 2–5 nm and the N-doping content was 6.56%. The size distribution and shell thickness of the prepared NCD@ZnO MCs were 100–200 nm and 30–90 nm, respectively. The encapsulation efficiency of NCDs was 34.69 ± 3.04%. The release behavior of NCD@ZnO MCs exhibited a dependence on salt concentration. Electrochemical impedance spectroscopy (EIS) measurements showed that NCD@ZnO MCs as fillers significantly improved the durability of the coating in terms of anti-corrosion resistance in all solutions with different salt concentrations. This smart filler is a promising candidate for application in anti-corrosive coatings, due to its low toxicity, facile synthetic route, near nanoscale size and sensitive environmental responsiveness.

中文翻译：

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负载氮掺杂碳点的盐响应 ZnO 微胶囊可增强耐腐蚀性

含有缓蚀剂的胶囊因其尺寸合适、效率高而在自修复腐蚀保护领域引起了广泛关注。ZnO由于其高度的结构可调性和独特的表面化学性质已成为一种很有前途的封装材料。同时，碳点（CDs）具有巨大的应用潜力，可以替代现有的有毒缓蚀剂。在此，开发了一种以掺氮碳点（NCDs）为核心材料，ZnO为壁材料（NCD@ZnO MCs）的耐腐蚀微胶囊，以完美发挥两种材料的优点。NCDs首先通过溶剂热法合成，然后在室温下搅拌制备NCD@ZnO MCs。表征了 NCDs 和 NCD@ZnO MCs 的形貌、微观结构和组成，分别。还讨论了NCD@ZnO MCs在提高水性涂料抗腐蚀性能方面的优越性。结果表明，获得的 NCDs 的尺寸分布为 2-5 nm，N 掺杂含量为 6.56%。制备的 NCD@ZnO MCs 的尺寸分布和壳厚度分别为 100-200 nm 和 30-90 nm。NCDs 的封装效率为 34.69 ± 3.04%。NCD@ZnO MCs 的释放行为表现出对盐浓度的依赖性。电化学阻抗谱（EIS）测量表明，NCD@ZnO MCs作为填料显着提高了涂层在所有不同盐浓度溶液中的耐腐蚀性能。这种智能填料由于其低毒性、