▎ 摘　　要

NOVELTY - Method for preparing graphene from carbon nanotubes involves (i) dispersing carbon nanotubes in a solvent at room temperature and coating the dispersion on the surface of a clean metal substrate, (ii) evaporating the solvent, sandwiching the carbon nanotubes by a metal substrate for rolling under room temperature without lubrication, rolling 1 time, folding the sample in half, continuing to roll, and repeating the half-folding and rolling to a certain number of passes, and (iii) gradually expanding the carbon nanotubes after the rolling to generate graphene. USE - The method is useful for preparing graphene from carbon nanotubes for preparation of graphene-reinforced metal composite material (claimed). ADVANTAGE - The method does not need to use chemical reagents, has simple process, no chemical pollution and high efficiency, obtains high-quality graphene with a low number of layers, is suitable for industrialized production, utilizes the graphene directly as a reinforcing body to achieve excellent balance between the strength and plasticity of the composite material, and breaks through the limitation of adding graphene volume fraction, so that the composite material can reach higher strength. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a use of the method for preparing graphene from carbon nanotubes for preparation of graphene-reinforced metal composite material, involving (A) dispersing carbon nanotubes in a solvent at room temperature and coating the dispersion on the surface of a clean metal substrate, (B) evaporating the solvent, sandwiching the carbon nanotubes by a metal substrate for rolling at room temperature without lubrication, rolling 1 time, folding the sample in half, continuing to roll, and repeating the folding and rolling to a certain number of passes to obtain intermediate sample, (C) hot-rolling the intermediate sample at a certain temperature, and (D) obtaining the product after the rolling is completed.