▎ 摘　　要

NOVELTY - Method for preparing graphene-carbon nanotube composite material by (i) stripping carbon nanotubes and placing multi-walled carbon nanotubes in concentrated nitric acid, performing reflux treatment at 80-100 degrees C to peel off the multi-walled carbon nanotubes into less than 20 layers of carbon nanotubes, naturally cooling to room temperature, after washing the solid with hydrochloric acid, dialyzing and drying to obtain the exfoliated carbon nanotubes, (ii) placing the exfoliated carbon nanotubes in solution of dispersed graphene and dispersing the carbon nanotubes and graphene in the solution to obtain graphene-carbon nanotube mixed solution, and (iii) subjecting the mixed solution of graphene-carbon nanotubes to hydrothermal reaction, and increasing the temperature to 150-180 degrees C at a rate of 1-5 degrees C per minute for 10-15 hours, naturally cooling to generate graphene-carbon nanotube gel, cleaning the gel with deionized water and freeze-drying to obtain the product. USE - Method for preparing graphene-carbon nanotube composite material. ADVANTAGE - The method improves the preparation of functional materials and broadens the application of carbon composites. DETAILED DESCRIPTION - Method for preparing graphene-carbon nanotube composite material by (i) stripping carbon nanotubes and placing multi-walled carbon nanotubes in concentrated nitric acid, performing reflux treatment at 80-100 degrees C to peel off the multi-walled carbon nanotubes into less than 20 layers of carbon nanotubes, after the reflow treatment is finished, naturally cooling to room temperature of 20-25 degrees C, after washing the solid with hydrochloric acid, dialyzing and drying to obtain the exfoliated carbon nanotubes, (ii) placing the exfoliated carbon nanotubes in solution of dispersed graphene in a mass ratio of (1-3):(1.5-4) and uniformly dispersing the carbon nanotubes and graphene in the solution to obtain graphene-carbon nanotube mixed solution, where the graphene comprises graphene oxide, reduced graphene oxide, or graphene, and (iii) subjecting the mixed solution of graphene-carbon nanotubes to hydrothermal reaction, so that the graphene and carbon nanotubes are hydrothermally self-assembled at 20-25 degrees C at a temperature rising rate of 1-5 degrees C per minute to 80-90 degrees C and holding the reaction for 1-5 hours, and again increasing the temperature to 150-180 degrees C at a rate of 1-5 degrees C per minute for 10-15 hours, after the reaction is completed, naturally cooling to room temperature of 20-25 degrees C to generate graphene-carbon nanotube gel, cleaning the gel with deionized water and freeze-drying to obtain the product.