Growth of vanadium dioxide nanostructures on graphene nanosheets

The metal oxide/graphene hybrid nanomaterials have been known as promising functional materials for advanced applications such as high capacitive electrode material of secondary batteries, and high sensitive material of high performance gas sensors. Here, morphology controlled vanadium dioxide (VO2) nanostructures were grown on Si wafer and exfoliated graphene by the vapor transport method using a horizontal furnace system. One-dimensional VO2 nanowires were grown on SiO2(300 nm)/Si substrate under 0.4 kPa condition. On the other hand, thick polycrystalline of VO2 platelets were grown on exfoliated graphene nanosheets under 0.4 kPa condition. In addition, polycrystalline VO2 platelets were only grown on exfoliated graphene nanosheets under 101 kPa (atmospheric pressure) condition. The growth of polycrystalline VO2 platelets on graphene nanosheets in atmospheric pressure condition is attributed to preferential growth on functional group of graphene surface such as carbonyl. The functional group is served as nucleation site of VO2 nanostructures.