Preparation of novel Au-Nb ₃O ₇F nanosheets for the photodegradation of tetracycline hydrochloride

Water pollution caused by antibiotics is a growing problem and photodegradation by efficient catalysts is an environmentally friendly technology that can effectively degrade organic pollutants in water. Here, a novel method was innovatively used to synthesize niobium oxyfluoride (Nb ₃O ₇F) nanosheets decorated with Au nanoparticles, which is the first report for the composites of Au and Nb ₃O ₇F. We prepared the Nb ₃O ₇F nanosheets via hydrothermal synthesis followed by deposition of Au nanoparticles on their surface using HAuCl ₄. The prepared samples were characterized by XRD, HRTEM, XPS, and UV–Vis. The diameters of most Au NPs are ranging from 5 to 25 nm with an average size of about 16.9 nm, as well as the Nb ₃O ₇F nanosheets in size ranging from 200 nm to 700 nm. The chemical composition of the Au-Nb ₃O ₇F showed a Au/Nb atomic ratio of 1/10, as well as a Nb/O/F ratio of 3/7/1. UV–Vis spectrum reveals a largest absorption peak at 520 nm for the Au-Nb3O7F nanosheets. The prepared Au-Nb ₃O ₇F nanomaterials were applied to the visible-light photodegradation of tetracycline hydrochloride, with the photocatalytic degradation rate reached more than 50% under the optimal conditions within 1 h. Capture experiments indicated that h ⁺ and •O ₂ ^- are the main active substances involved during the course of the photodegradation. Furthermore, the proposed mechanism for the photodegradation of the novel Au-Nb3O7F nanosheets was given.