▎ 摘　　要

Graphene-like g-C3N4 nanosheet (GCN)/Fe3O4 quantum dot (QD) nanocomposites were successfully synthesized by a facile electrostatic self-assembly method. Characterization shows that the GCN is at least several micrometers in size. The GCN/Fe3O4 nanocomposites were used as photocatalysts for degradation of Rhodamine B (RhB) under visible light irradiation. After irradiation for 1.5 h, the degradation efficiency was 72.5% for pure g-C3N4, 81% for GCN-1 wt% Fe3O4, 95% for GCN-2 wt% Fe3O4, 60.46% for GCN-3 wt% Fe3O4 and 57.2% for GCN-4 wt% Fe3O4, indicating that GCN-2 wt% Fe3O4 nanocomposites had the highest photocatalytic activity. We deduce that the efficient separation of the photogenerated electron-hole pairs and the high specific surface area of GCN play important roles in the photocatalytic activity of the nanocomposites. In addition, the nanocomposites can be loaded with a model drug (Rhodamine B) and the loading capacity was as high as 108.6 mg g(-1), making it a potential candidate for photocatalysis and controlled magnetically targeted drug delivery.