Fabrication of hierarchical nanostructures is an important way for performance improvement and application expansion of nanomaterials. It is still a great challenge to synthesize three dimensional hierarchical graphene nanostructures with controlled secondary structures and primary building units, because it is difficult to realize effective control of graphene layer morphology and necessary arrangement of graphene. In this work, a “complex-directed” strategy has been successfully developed for the synthesis of three dimensional graphene nanostructures. Especially, the obtained three dimensional graphene nanostructures are quite regular in morphology, they can be nanorods or regular particles, composed of hollow graphene nanospheres with different layers. The morphology and the structure of these nanostructures, including primary building units and secondary structures are strongly dependent on the amount of HCl solution. The obtained three-dimensional graphene nanostructure can serve as an excellent candidate for electrode material of electric double layer capacitors (EDLCs) and present outstanding electrochemical behaviors. This is mainly due to the excellent electrical conductivity of graphene hollow nanospheres and the porous structures conducive to ion diffusion and electron transport.

分层纳米结构的制备是提高纳米材料性能和扩展其应用范围的重要途径。合成具有受控二级结构和一级结构单元的三维分层石墨烯纳米结构仍然是一个巨大的挑战，因为很难实现对石墨烯层形态的有效控制和石墨烯的必要排列。在这项工作中，已经成功地开发了一种“复杂的定向”策略，用于合成三维石墨烯纳米结构。特别地，所获得的三维石墨烯纳米结构在形态上是非常规则的，它们可以是纳米棒或规则的颗粒，由具有不同层的中空石墨烯纳米球组成。这些纳米结构的形态和结构，包括主要建筑单元和次要结构在内的各种溶液都强烈依赖HCl溶液的量。所获得的三维石墨烯纳米结构可作为双电层电容器（EDLC）电极材料的极佳候选者，并具有出色的电化学性能。这主要归因于石墨烯中空纳米球的优异电导率以及有助于离子扩散和电子传输的多孔结构。