Carbon nanostructure preparation method, carbon nanostructure prepared by means of same, and composite material comprising same

A method for producing carbon nanostructures, comprising allowing a catalyst and reactant gases comprising a carbon source to flow in a fluidized bed reactor to synthesize carbon nanostructures wherein some of the carbon nanostructures remain uncollected and are used as fluidic materials in the fluidized bed reactor and wherein the residual rate of the fluidic materials is from 0.4 to 0.7, as calculated by Equation 1:

• Residual rate of carbon nanostructures=Volume of remaining carbon nanostructures/(Volume of initially remaining carbon nanostructures+Volume of as-produced carbon nanostructures) [Equation 1]