Preparation method of eggplant peel modified magnetic iron-zinc nano photocatalyst

The invention discloses a preparation method of an eggplant peel modified magnetic iron-zinc nano photocatalyst, iron-zinc raw materials are extracted from waste zinc-manganese batteries, an eggplant peel leaching solution is used for modification, the whole process is simple and efficient, and resource utilization of the waste batteries and eggplant peel can be realized; the eggplant peel extract liquid is used as a dispersing agent to modify iron and zinc, so that agglomeration of the nano material can be remarkably reduced, and the eggplant peel extract liquid is used as a stabilizing agent to reduce ion leaching of the photocatalytic material; in addition, anthocyanin in the eggplant peel extract liquid can reduce iron ions and zinc ions to form a composite valence iron-zinc nano-photocatalyst, so that a typical N-type heterostructure is formed, and the photocatalytic performance of the composite valence iron-zinc nano-photocatalyst is improved; the iron-zinc nano photocatalyst prepared by a sol-gel metho