The invention relates to a preparation method and application of panchromatic luminous carbon dots sourced from tobacco waste. The preparation method comprises the following steps: step 1,
drying tobacco waste, and crushing to obtain tobacco waste chippings; step 2, uniformly mixing one of water, absolute ethyl
alcohol and
acetone with the tobacco waste chippings and H2O2, standing for 5-30 minutes, and performing ultrasonic treatment by utilizing ultrasonic
waves; step 3, filtering out tobacco waste debris residues to obtain a
carbon dot crude solution containing
blue carbon dots, green carbon dots and red carbon dots; 4, further filtering the
carbon dot crude solution through a 0.22 mu m filter membrane, and dialyzing in
ultrapure water to obtain a
carbon dot concentrated solution; and 5, carrying out rotary
evaporation on the carbon dot crude solution in a
rotary evaporator at the temperature of 30-50 DEG C until the carbon dot crude solution is dried to obtain a carbon dot
solid. By utilizing the tobacco waste, the problems of environmental
pollution and resource waste caused by improper treatment of the tobacco waste are solved; compared with the existing method, the method is simpler in process, reduces the utilization of harmful chemical substances, and is suitable for large-scale production.