Preparation, Characterization, and Biotoxicity of Nanosized Doped Zno Photocatalyst

Metal-doped nanosized ZnO (nZnO) photocatalyst has been widely used for its typical properties and has thus gained considerable attention. In this study, five types of nZnO (nondoped nZnO, iron- (Fe-) doped nZnO, cobalt- (Co-) doped nZnO, nickel- (Ni-) doped nZnO, and manganese- (Mn-) doped nZnO) materials were prepared through a wet chemical method and then exposed toDaphnia magna(D. magna) at low and high concentrations (50 and 250 μg L−1). Results showed that the different metal-doped nZnOs had a variety of shapes and sizes and exhibited diverse dissolubility. After exposure tests, Zn accumulation, metallothionein (MT), and malondialdehyde (MDA) contents inD. magnaunder 250 μg L−1were significantly higher than those in the 50 μg L−1groups. Compared with nondoped nZnO, Co-doped and Ni-doped nZnO enhanced Zn accumulation inD. magnawhereas Mn-doped nZnO reduced such accumulation. MT and MDA contents in metal-doped nZnO (except Ni-nZnO) treatments were lower than those in nondoped nZnO. Zn accumulation showed a negative relationship with dissolved Zn percentage, which can be explained by the swallowing of nZnO particles as an important pathway ofD. magnaingestion. Sizes, dissolubility, and physiological functions of doping metals were the influencing factors on metal-doped nZnO biotoxicity toD. magna.