Carbon quantum dot composite material as well as preparation method and application thereof

The invention discloses a method for preparing a carbon quantum dot composite material, which comprises the following steps: 1) using an acid absorption tobacco extracting solution as a carbon source, and carrying out first hydrothermal reaction to obtain a carbon quantum dot solution; 2) performing first freeze drying on the carbon quantum dot solution to obtain colloidal carbon quantum dots; and 3) uniformly mixing the colloidal carbon quantum dots, polyaniline and graphene oxide in water, carrying out a second hydrothermal reaction, and then carrying out second freeze drying to obtain the carbon quantum dot-polyaniline-reduced graphene oxide composite material. The invention further provides the carbon quantum dot composite material and application thereof. According to the method for preparing the carbon quantum dot composite material provided by the invention, the tobacco waste liquid which is toxic and harmful to the environment is converted into the available carbon quantum dots, so that the discharge