Preparation method and application of tailings-based zeolite@CDs-TiO2 composite photocatalyst

A preparation method of a tailings-based zeolite@carbon dots-titanium dioxide (CDs-TiO2) composite photocatalyst, comprising:

• step 1:
• tailings pretreatment, comprising:
• performing an acidification treatment on tailings powder by immersing the tailings powder into acid liquor and stirring evenly to obtain acidified tailings powder;
• roasting the acidified tailings powder at a temperature of 700-900 Celsius degrees (° C.) under a nitrogen (N2) preservation and then keeping the temperature unchanged to obtain modified tailings powder;
• wherein the acidification treatment comprises:
• adding the tailings powder into diluted hydrochloric acid with a molar concentration of 1 molar per liter (M) and performing an ultrasonic treatment on the diluted hydrochloric acid added with the tailings powder for 1.5-2.5 hours (h);
• step 2:
• adding titanium dioxide (TiO2) and the modified tailings powder into lye sequentially and stirring to obtain a mixed suspension, wherein a weight ratio of the TiO2 and the modified tailings powder is in a range of 0.5-1;
• and stirring and aging the mixed suspension for 8-16 h under a condition of ultraviolet irradiation to obtain an aged suspension;
• wherein a light intensity of the ultraviolet irradiation is in a range of 10-20 milliwatts per square centimeter (mW/cm2);
• and the lye is sodium hydroxide (NaOH) solution with a molar concentration of 1-3 M;
• and
• step 3:
• performing a hydrothermal reaction on the aged suspension to obtain a product, filtering the product to obtain a filtered product, and washing and drying the filtered product to obtain the tailings-based zeolite@CDs-TiO2 composite photocatalyst;
• wherein a temperature of the hydrothermal reaction is in a range of 115-125° C., and a period of the hydrothermal reaction is in a range of 20-30 h.