Gas-Phase Self-Assembly of Highly Ordered Titania@Graphene Nanoflakes for Enhancement in Photocatalytic Activity

The gas-phase self-assembly of reduced graphene oxide (rGO) nanoflakes with highly ordered ultrafine titania (TiO2) particles was performed and the resultant hybrid material displayed an enhanced photocatalytic performance, both in producing hydrogen and in degrading dyes. Freshly synthesized TiO2 nanoparticles (∼35 nm in equivalent mobility diameter) were quantitatively incorporated with nanoscale rGO (∼36 nm in equivalent mobility diameter) in the form of TiO2/rGO hybrid nanoflakes (∼31 nm in equivalent mobility diameter). The TiO2/rGO hybrid flakes were finally employed to evaluate its photocatalytic activity, and it was found that the ability to achieve hydrogen production and dye degradation was greater than that of a hybridized material from commercial p25-TiO2 and large rGO. This gas-phase self-assembly also enhanced the photocatalytic activity by applying different spark configurations to prepare ZnO, Au, or Ag particles incorporated with rGO nanoflakes.