Confined Chemical Transformation of Melamine in Graphite Interlayers Toward Graphite-Based Composites with Nitrogen-Rich Two-Dimensional Materials

Graphite-based nanocomposites with nitrogen-rich covalent two-dimensional materials are promising for energy, catalytic and sensing applications, but their controlled construction remains challenging because both graphite and many covalent 2D materials consist of stacked sheets that are difficult to integrate homogeneously without prior exfoliation, dispersion, mixing, and restacking. Here, we explore a solvent-free strategy that uses melamine-confined graphite as a preorganized precursor for chemical transformations between graphene layers. We demonstrate that intercalated melamine can undergo reaction pathways analogous to those of bulk melamine, enabling not only the previously reported formation of graphite/g-C3N4 composites but also the construction of a new graphite/melem composite. The same concept is further extended to multicomponent solid-state reactions by introducing pyromellitic dianhydride, enabling the formation of new graphite/polyimide-linked two-dimensional material composites from either melamine or melem precursors. Comparison of one-pot and stepwise routes shows that precursor preorganization within graphite improves framework preservation, structural continuity, and morphological homogeneity. Overall, this work presents graphite interlayers as confined reaction environments for transforming simple nitrogen-rich molecules into integrated graphite/2D-material composites, providing a scalable platform for exploring solid-state chemistry and hybrid material synthesis between graphene layers.