In-situ synthesis of a plasmonic Ag/AgCl/Ag2O heterostructures for degradation of ciprofloxacin

Ciprofloxacin (CIP) has caused serious environmental problems because of its high resistance to conventional wastewater treatments methods. To improve the photodegradation efficiency for CIP, a new system of Ag/AgCl/Ag2O is developed by growth of Ag/AgCl on the surface of Ag2O nonoparticles at room temperature. The stable Ag/AgCl nanoshells could efficiently protect inner Ag2O from photocorrosion during the photocatalytic process and enhance the separation and transfer efficiency of photo-induced electron-hole pairs. The optimum photocatalytic efficiency of 50% Ag/AgCl/Ag2O heterostructures for the degradation of CIP under visible light irradiation (lambda >420 nm) was about 2.9 and 3.73 times higher than that of individual Ag2O and Ag/AgCl, respectively. The radical trap experiments showed that the degradation of CIP was driven mainly by the participation of superoxide radical (O2(-center dot)) and the action of holes (h(+)). From the experimental results and the relative band gap position of these semiconductors, a possible Z-scheme photocatalytic mechanism was proposed. The system has greatly overcome the drawbacks of single component Ag2O and realized the strong redox ability and long-term stability. (C) 2016 Elsevier B.V. All rights reserved.