Core-shell structured metal-organic framework-derived carbon with redox-active polydopamine nanothin film

In this study, three-dimensional (3D) ZIF-8-derived carbon (ZIF-8C) polyhedrons have been successfully coated with polydopamine (PDA) nanothin layer via a facile synthetic method that exploits oxidative self-polymerization of dopamine in alkaline solutions. It is observed that ca. 20 nm of PDA nanothin film is coated on ZIF-8C surface with a good homogeneity. Our results show clear morphological changes in core-shell structured PDA-coated ZIF-8C (ZIF-8C@PDA) as compared to bare ZIF-8C. In addition, the cyclic voltammetry shows conspicuous redox peaks in ZIF-8C@PDA. The observed redox activity is attributed to a series of redox reactions of oxygen species of catechol and quinone groups of PDA. With superior adhesive property and redox activity as additional surface functionality, ZIF-8C@PDA can be used in various applications, especially in energy storage applications in the future.