▎ 摘　　要

NOVELTY - Preparing three-dimensional graphene/carbon nanotube composite material comprises (i) decomposing expandable graphite into expanded graphite by microwave, and preparing graphene oxide by modified Hummers method, and dissolving in water, (ii) adding carbon nanotubes, dispersing at high speed, and performing high-power ultrasonic dispersion, (iii) adding reducing agent and uniformly stirring, performing the first stage boiling water bath reaction, and transferring to -18 degrees C to freeze, taking out and returning to room temperature, and performing the second stage boiling water bath reaction to obtain a three-dimensional graphene/carbon nanotube composite pre-product, and (iv) calcining the pre-product of the three-dimensional graphene /carbon nanotube composite material obtained in the step (iii) at high temperature. USE - The three-dimensional graphene/carbon nanotube composite material is useful for aqueous electromagnetic shielding coating (claimed). ADVANTAGE - The method: is simple and environmentally friendly, and is suitable for industrial scale production. DETAILED DESCRIPTION - Preparing three-dimensional graphene/carbon nanotube composite material f comprises (i) decomposing expandable graphite into expanded graphite by microwave, and preparing graphene oxide by modified Hummers method, and dissolving in water to ultrasonically peel off to obtain graphene oxide dispersion, (ii) adding carbon nanotubes to the graphene oxide dispersion in the step (i), dispersing at high speed, and performing high-power ultrasonic dispersion to obtain uniformly dispersed graphene oxide/carbon nanotube mixed solution, (iii) adding reducing agent to the graphene oxide/carbon nanotube dispersion in the step (ii) and uniformly stirring, performing the first stage boiling water bath reaction, and transferring to -18 degrees C to freeze, taking out and returning to room temperature, and performing the second stage boiling water bath reaction to obtain a three-dimensional graphene/carbon nanotube composite pre-product, and (iv) calcining the pre-product of the three-dimensional graphene / carbon nanotube composite material obtained in the step (iii) at high temperature.