ZnO nanoflowers photocatalysis of norfloxacin: Effect of triangular silver nanoplates and water matrix on degradation rates

Norfloxacin (NF) is an effective antimicrobial drug that poses a threat to human health because of its environmental residues. In this research, ZnO nanoflowers and triangular silver nanoplates (T-Ag) were synthesized using a facile sol-gel method. The synergistic photocatalytic effects of the adding different triangular silver nanoplates concentration over ZnO nanoflowers on the NF removal under visible light was studied for the first time. Photodegradation results demonstrated that T-Ag could significantly enhance the activity of ZnO nanoflowers. The degradation efficiency of NF by T-Ag/ZnO nanoflowers was affected in the different water matrices, including ultra-pure, tap, and river water. The effects of the dosage of ZnO nanoflowers, initial NF concentration, and pH on the photocatalytic activity of ZnO nanoflowers were also explored. The results show that the highest rate constant for the degradation of NF is obtained with 1 mg L-1 of T-Ag, 0.1 g L-1 of ZnO, initial NF concentration of 10 mg L-1, and pH of 11 in ultra-pure water. The possible mechanism of the photocatalytic degradation of NF using T-Ag/ZnO nanoflowers through the addition of scavenger agents (i.e., EDTA and methanol) was also studied. (C) 2016 Published by Elsevier B.V.