Sub-coherent growth of ZnO nanorod arrays on three-dimensional graphene framework as one-bulk high-performance photocatalyst

Highly ordered ZnO nanorod arrays were grown vertically on the surface of three-dimensional graphene (3DG) framework bulk to prepare a one-bulk structure. In such structure, ZnO exhibits outstanding photocatalyst performance due to its hybridization with 3DG. The sub-coherency between ZnO and 3DG ensures the template-free growth of ZnO nanorod arrays and the exposing of its most active crystal surfaces {0001}. The hybridization prevents the agglomeration of ZnO nanoparticles, helping the formation of nanorod array morphology, enhancing the mass transfer of reactants and the separation of photogenerated holes. In the efficiency test, with tiny amount of ZnO catalyst (∼5.03 × 10−3 g), the concentration of methyl orange decreased to ∼11% of the initial value within four hours. The structure possesses high average photocatalytic efficiency of 6.56 × 10−3 h−1, much higher than that of bare ZnO nanorods.