N-doped carbon hollow sphere reservoirs containing Zn2+-mercaptobenzoxazole with pH-responsive function to fabricate a high-performance corrosion protective epoxy coating for aluminum alloy

In this article, a core/shell structure based on zinc salt of 2-mercaptobenzoxazole (Zn.MBO) and N-doped carbon hollow sphere (NCHS) was synthesized and characterized. The active corrosion protection performance of the encapsulated Zn.MBO in NCHS (Zn.MBO@NCHS) was assessed on bare and epoxy-coated AA2024. The MBO and zinc cation release from the capsules was analyzed at different pHs. The electrochemical impedance spectroscopy results proved that, in the presence of Zn.MBO@NCHS, the corrosion resistance of the scratched coated samples after 72 h immersion was significantly higher than the rest of samples indicating its active inhibitive function.

Automated summary

A core/shell structure based on zinc salt of 2-mercaptobenzoxazole (Zn.MBO) and N-doped carbon hollow sphere (NCHS) was synthesized and characterized in this study. The corrosion protection performance of the encapsulated Zn.MBO in NCHS (Zn.MBO@NCHS) was evaluated on bare and epoxy-coated AA2024. The release of MBO and zinc cation from the capsules was analyzed at different pH levels. The electrochemical impedance spectroscopy results demonstrated that Zn.MBO@NCHS significantly enhanced the corrosion resistance of the scratched coated samples after 72 hours of immersion, indicating its active inhibitive function.