Bismuth-based compounds crystals growth on graphene with various degrees of oxidation

International audienceThe crystal growth of Bismuth-based compounds (mainly Bi2O2CO3) on graphene with various degrees of oxidation in hydrothermal process is reported. The graphene sheets with different concentrations of oxygen-containing groups and defects, as a special carbon source, can effectively influence the phase compositions, morphologies and even photoelectric properties of graphene-Bi2O2CO3 composites through the binding behavior of graphene oxide in the nucleation and growth process of Bi2O2CO3 crystals. The cube-like crystals including mainly Bi2O2CO3 phase with Bi2O3 tightly wrapped by numerous graphene sheets are synthesized employing highly oxidized graphene oxide (HGO) as starting materials, while the partially oxidized graphene oxide (PGO) is used for synthesizing 3D flower-like hierarchical Bi2O2CO3 microstructures just containing Bi2O2CO3 phase adorned with sporadic graphene sheets. Furthermore, the higher charge separation yield is achieved for cubic composites with much more interfacial connection between the cube-like crystals and graphene sheets compared to flower-like crystals. The above results suggest an interesting approach for controlling the morphology and property of crystals by tuning the functional groups on graphene sheets used in the nucleation and growth process of crystals. (C) 2016 Published by Elsevier B.V