High-activity visible-light-driven photocatalyst for wastewater treatment and preparation method thereof

The invention relates to a high-activity visible-light-driven photocatalyst for wastewater treatment and a preparation method thereof, in particular to a fly ash floating bead loaded core-shell structured high-activity visible-light-driven photocatalyst for wastewater treatment. The core of the photocatalyst is fly ash floating beads with the diameter of 0.075-0.85 mm, and the shell of the photocatalyst is a visible-light-driven photocatalyst active component with the thickness of 100-500 nm; the visible-light-driven catalyst comprises the following components in percentage by mass: 1%-5% of nano TiO2, 2%-10% of nano Bi2O3, 5%-15% of graphene doped nano SiO2 and 75%-87% of fly ash floating beads; The specific gravity is 0.45-0.95 g/cm < 3 >; and the specific surface area is 10-50 m < 2 >/g; The visible-light-driven photocatalyst is formed by drying a visible-light-driven photocatalyst precursor hydrosol coating the fly ash floating beads to form a gel film and then sintering the gel film at 500-700 DEG C. The