Preparation of porous G—C3N4 tubes in-situ anchored by waste biomass-derived carbon dots and its application in aflatoxin removal

A method for preparing a SA@CDs/g-C3N4 composite material, comprising:

• adding a CDs/g-C3N4 compound into water, and uniformly dispersing same through ultrasonic treatment;
• adding sodium alginate, intensely stirring and fully mixing a mixture, and forming a pregel solution;
• transferring the fully mixed pregel solution into a mold, and freeze-drying the pregel solution to obtain sponge;
• and soaking the sponge in a CaCl2) solution for gel, performing washing with deionized water, performing freeze-drying, and obtaining the SA@CDs/g-C3N4 composite material;
• wherein
• a mass-volume ratio of the CDs/g-C3N4 compound to the water is within 1:300-1:800, g/mL, a mass ratio of the CDs/g-C3N4 compound to the sodium alginate is within 1:4-1:10, and a concentration of the CaCl2) solution is within 1 wt %-8 wt %;
• a method for preparing the CDs/g-C3N4 compound comprises:
• adding melamine and thiocyanuric acid into water, and stirring evenly a mixture;
• adding a CDs solution and stir evenly a mixture;
• and filtering, washing, drying and transferring a mixed solution to a muffle furnace for high-temperature calcination, and obtaining the CDs/g-C3N4 compound;
• wherein
• a molar ratio of melamine to the thiocyanuric acid is within 1:0.5-1:1.5, and the high-temperature calcination is performed under the following conditions:
• heating is performed to 550° C.-650° C. at a rate of 2° C./min-6° C./min, and calcination is performed at this temperature for 3 h-6 h;
• and
• a method for preparing the CDs solution comprises:
• placing an orange juice in a reactor lined with polytetrafluoroethylene, and heating at 180° C.-210° C. for 8 h-12 h;
• and performing natural cooling, centrifuging and filtering a reaction product, and forming a transparent brownish-yellow carbon quantum dot solution, that is, the CDs solution.