Figure 1: Schematic representation of the formation mechanism for the superlattice through space-confined nanoreactor strategy.

VO(acac)2 is firstly hydrolysed to yield [VO(H2O)5]2+, then intercalated into the interlayers of RGO nanosheets. The intercalated [VO(H2O)5]2+ condenses to VO6 octahedra in the RGO interlayers formed space-confined nanoreactor. Finally the VO6 octahedra further condenses to yield vanadium oxide nanosheets in the interlayers of RGO nanosheets, resulting in the formation of the superlattice.