Eu-doped Bi4O5I2 composite nanometer photocatalyst and preparation method thereof

The invention discloses an Eu-doped Bi4O5I2 composite nanometer photocatalyst. The photocatalyst is prepared by taking bismuth nitrate, sodium iodide and europium nitrate as raw materials through a hydrothermal method. The specific preparation method comprises the following steps: S1, dissolving bismuth nitrate in a nitric acid water solution to form a solution A, and dissolving NaI in another nitric acid water solution to form a solution B; S2, slowly and dropwise adding the solution B into the solution A, and carrying out stirring to obtain a deep red BiOI solution; S3, adding an alkali liquor into the BiOI solution to adjust the pH value to 10 to obtain a white solution; S4, adding europium nitrate and sodium dodecyl benzene sulfonate into the white solution, and carrying out stirring until solids are completely dissolved to obtain a mixed solution; S5, transferring the mixed solution into a Teflon reaction kettle, carrying out heating to 120-180 DEG C, carrying out a reaction for 6-24 hours to generate a