Alternately aligned 2D heterostructures enabled by d-spacing accessible, highly periodic accordion-like graphene oxide frameworks

Two-dimensional (2D) heterostructures hold great promise in designing integrated materials, while the current synthesis strategies still confront challenges for multilayer heterostructure construction and scale-up production. Here we report a generalized host-guest strategy based on non-exfoliated layered graphene oxide (LGO) to construct graphene-based heterostructures that consist of multilayered, alternately aligned graphene and metal oxide nanosheets. The 2D-aligned GOs and open interlayer spaces make LGO an ideal platform to create periodic 2D host frameworks. Polyetheramine oligomers covalently bond the adjacent GOs. The extended chain conformation endows the resulting accordionlike GO frameworks with high structural stability, periodicity and enlarged interlayer space. Owing to the high affinity of the open and well-arranged 2D channels toward guest precursors, a variety of high-quality heterostructures can be synthesized. Furthermore, a variety of exfoliated, ultrathin metal oxide nanosheets can also be prepared by removing the graphene skeleton. The flexible interlayer chemistry presented in this study paves a way toward the synthesis of a large family of graphene-inorganic/organic 2D heterostructures.