No abstract

Graphene and carbon nanotubes are nanometer-sized carbon materials with the characteristics of the great specific surface area, good electrical conductivity and excellent mechanical properties. Selecting appropriate methods to prepare graphene/carbon nanotube composites can generate a synergistic effect between them with many physical and chemical properties enhanced, and these composites have a great future in many areas. In this paper, some kinds of preparation methods about graphene/carbon nanotube composites were described in detail, such as chemical vapor deposition, layer by layer deposition, electrophoretic deposition, vacuum filtration, coating membrane and in situ chemical reduction method. The advantages and disadvantages of these methods were compared as table format. To further enhance the functions, the graphene/carbon nanotube composites were doped with other materials such as polymer materials, nanoparticles, metal oxide to achieve the purpose of modification. Some researchers proposed theoretical computer model design for some special composites structures such as three-dimensional columnar structure and spiral structure to improve the performance of composites. Meanwhile, the applications of composites in supercapacitor, a photoelectric conversion device, energy storage batteries, electrochemical sensors and other fields were discussed in detail. These applications fully proved that composites had a brighter future than pure graphene or carbon nanotube. In addition, the developments of composites are prospected. Preparations of grapheme/carbon nanotube composites are maturing, but a variety of methods have their drawbacks and shortcomings, to get preparation method with easy control operation, low production costs, high raw material utilization, good product quality needs further research and exploration. Preparations of the highly oriented columnar structures between the layers of graphene and carbon nanotube and three-dimensional structure with graphene helicaly inserted or wrapped carbon nanotubes still remain in the computer model. In the near future the studies of the composites will be deepen and extended to develop new fields.