Oxidative degradation of the antibiotic oxytetracycline by Cu@FeO core-shell nanoparticles.

A core-shell nanostructure composed of zero-valent Cu (core) and FeO (shell) (Cu@FeO) was prepared by a simple reduction method and was evaluated for the degradation of oxytetracycline (OTC), an antibiotic. The Cu core and the FeO shell were verified by X-ray diffractometry (XRD) and transmission electron microscopy. The optimal molar ratio of [Cu]/[Fe] (1/1) in Cu@FeO created an outstanding synergic effect, leading to >99% OTC degradation as well as HO decomposition within 10min at the reaction conditions of 1g/L Cu@FeO, 20mg/L OTC, 20mM HO, and pH3.0 (and even at pH9.0). The OTC degradation rate by Cu@FeO was higher than obtained using single nanoparticle of Cu or FeO. The results of the study using radical scavengers showed that OH is the major reactive oxygen species contributing to the OTC degradation. Finally, good stability, reusability, and magnetic separation were obtained with approximately 97% OTC degradation and no notable change in XRD patterns after the Cu@FeO catalyst was reused five times. These results demonstrate that Cu@FeO is a novel prospective candidate for the pharmaceutical and personal care products degradation in the aqueous phase.