Tunable interlayer distance in graphene oxide through alkylamine surface coverage and chain length

Layered materials have unique structures that can be modified by adjusting the space between layers through pillaring or surface functionalization. Unlike typical crystalline layered materials, graphene oxide (GO) possesses reactive oxygenated functional groups, which lead to spontaneous reduction and stacking upon thermal treatment. Here, we investigated the functionalization of GO with different amounts of hexylamine to control the degree of surface coverage. Furthermore, octylamine and dodecylamine were employed to confirm the effect of the alkyl chain length on the interlayer distance of the resultant GO derivatives. Subsequent thermal treatment produced reduced GO (rGO) functionalized with alkylamines, demonstrating the retention of the interlayer distance. Additionally, amine-functionalized rGOs exhibited varying porous structures.