Nanographene-constructed carbon nanofibers grown on graphene sheets by chemical vapor deposition: high-performance anode materials for lithium ion batteries.

We report on the fabrication of 3D carbonaceous material composed of 1D carbon nanofibers (CNF) grown on 2D graphene sheets (GNS) via a CVD approach in a fluidized bed reactor. Nanographene-constructed carbon nanofibers contain many cavities, open tips, and graphene platelets with edges exposed, providing more extra space for Li(+) storage. More interestingly, nanochannels consisting of graphene platelets arrange almost perpendicularly to the fiber axis, which is favorable for lithium ion diffusion from different orientations. In addition, 3D interconnected architectures facilitate the collection and transport of electrons during the cycling process. As a result, the CNF/GNS hybrid material shows high reversible capacity (667 mAh/g), high-rate performance, and cycling stability, which is superior to those of pure graphene, natural graphite, and carbon nanotubes. The simple CVD approach offers a new pathway for large-scale production of novel hybrid carbon materials for energy storage.

Facile synthesis of graphene nanosheets via Fe reduction of exfoliated graphite oxide.

The synthesis of graphene nanosheets from graphite oxide typically involves harmful chemical reductants that are undesirable for most practical applications of graphene. Here, we demonstrate a green and facile approach to the synthesis of graphene nanosheets based on Fe reduction of exfoliated graphite oxide, resulting in a substantial removal of oxygen functionalities of the graphite oxide. More interestingly, the resulting graphene nanosheets with residual Fe show a high adsorption capacity of 111.62 mg/g for methylene blue at room temperature, as well as easy magnetic separation from the solution. This approach offers a potential for cost-effective, environmentally friendly, and large-scale production of graphene nanosheets.