Enhancing the comprehensive corrosion resistance of waterborne epoxy coatings:Combination of Bimetal Nanocontainer ZIF-8-Ce and g-C3N4

In this study, we describe the synthesis of GP (g-C3N4@PDA) nanosheets via the encapsulation of g-C3N4 nanosheets with polydopamine (PDA). This encapsulation process serves to enhance the dispersion of the nanosheets in water, while also creating reaction sites for the subsequent loading of nanocontainers. Consequently, the GP nanosheets function as scaffolds for the in situ growth of pH-responsive ZIF-8-Ce nanocontainers, leading to the formation of GPZC (g-C3N4@PDA@ZIF-8-Ce) composite nanomaterials. Significantly, the porous structure of the g-C3N4@PDA@ZIF-8-Ce nanocontainer offers adsorption sites for benzotriazole (BTA). Through vacuum adsorption of a specific amount of benzotriazole, we successfully synthesize the composite nanomaterial GPZCB (g-C3N4@PDA@ZIF-8-Ce-BTA), which exhibits remarkable barrier and self-healing properties. To evaluate the comprehensive corrosion resistance of the composite coating incorporating GPZCB, a series of relevant performance tests were conducted. In the electrochemical test, the failure time of the GPZCB/sample was extended by 15 d. Additionally, the coating's durability time in the salt spray test was prolonged by 200 h.