▎ 摘　　要

NOVELTY - Preparing graphene/carbon nanotube/carbon nanofiber membrane ternary composite involves dissolving polyacrylonitrile in N,N-dimethylformamide solution to obtain polyacrylonitrile solution having concentration of 8-12 wt.%. The graphene oxide and carbon nano tube are mixed with obtained polyacrylonitrile solution ultrasonically and the solution is heated at 60 degrees C to obtain graphene oxide/carbon nanotube/polyacrylonitrile spinning solution, where mass ratio of graphene oxide, carbon nanotube and polyacrylonitrile solution are 1:0.05-0.15:08-12. USE - Method for preparing graphene/carbon nanotube/carbon nanofiber membrane ternary composite for capacitive desalting electrode(claimed). ADVANTAGE - The method enables to prepare graphene/carbon nanotube/carbon nanofiber membrane ternary composite in simple manner. The product has good electrical conductivity, good flexibility, improved desalting function and has good potential developing prospect. DETAILED DESCRIPTION - Preparing graphene/carbon nanotube/carbon nanofiber membrane ternary composite involves dissolving polyacrylonitrile in N,N-dimethylformamide solution to obtain polyacrylonitrile solution having concentration of 8-12 wt.%. The graphene oxide and carbon nano tube are mixed with obtained polyacrylonitrile solution ultrasonically and the solution is heated at 60 degrees C to obtain graphene oxide/carbon nanotube/polyacrylonitrile spinning solution, where mass ratio of graphene oxide, carbon nanotube and polyacrylonitrile solution are 1:0.05-0.15:08-12. The obtained graphene oxide/carbon nanotube/ polyacrylonitrile spinning solution is placed in a syringe and then electrospun by a syringe pump at constant flow rate of 0.8-1.2 milliliter/hours under a voltage of 18-20 kilovolt. The electrospun fibers are collected on a grounded aluminum foil, then the collected fiber paper is dried overnight and then stabilized in air at 260-280 degrees C for 1-2 hours at a heating rate of 1-2 degrees C/minutes to obtain pre-oxidized fibers. The obtained preoxidized fibrous membrane is transferred to a tubular furnace and then heated at 700-900 degrees C under a continuous flow of nitrogen for 1-3 hours. The nitrogen gas is then replaced with carbon dioxide to activate the nanofiber film for 1-2 hours to obtain graphene/carbon nanotube/carbon nanofiber membrane ternary composite capacitive desalting electrode.