Synthesis of 3D Hierarchical Fe3O4/Graphene Composites with High Lithium Storage Capacity and for Controlled Drug Delivery
journal contributionposted on 10.11.2011, 00:00 by Xiyan Li, Xiaolei Huang, Dapeng Liu, Xiao Wang, Shuyan Song, Liang Zhou, Hongjie Zhang
Three-dimensional (3D) hierarchical Fe3O4/graphene nanosheet (GNS) composites have been synthesized using a simple in situ hydrothermal method. Characterization shows that the Fe3O4 nanoflowers are highly encapsulated in a GNS matrix. The Fe3O4/GNSs-1 nanocomposite (60 wt % of Fe3O4 in the composites) exhibits a stable capacity of ∼605 mAh g–1 with no noticeable fading for up to 50 cycles in the voltage range of 0.001–3.0 V, and the superior performance of Fe3O4/GNSs-1 is clearly established by comparison of the results with those from Fe3O4/GNSs-2 (23 wt % of Fe3O4 in the composites) and bare Fe3O4. In addition, another possible application of the drug delivery with the composites shows that the loading of rhodamine B (RB) on Fe3O4/GNSs increased linearly with the increase in the initial RB concentration, and the loading capacity of Fe3O4/GNSs-1 was as high as 3.18 mg mg–1. The excellent electrochemical performance of the composites and highly efficient loading of RB could be attributed to the enhanced electronic conductivity and the large surface areas of the Fe3O4/GNSs in which the hierarchical structure of Fe3O4 nanoflowers are highly encapsulated in the GNS matrix.