Facile Preparation of a Plasmon-Enhanced Ag-CuO/TiO2 for the Efficient Visible-Light-Driven Photodegradation of Tetracycline Hydrochloride

Water pollution caused by antibiotics is a growing problem. Therefore, photodegradation by efficient catalysts is an environmentally friendly technology that can effectively degrade organic pollutants in water. In this work, a method was innovatively used to prepare a ternary heterostructure of plasmon-enhanced Ag-CuO/TiO2. The composite was synthesized through a facile stepwise strategy involving the formation of CuO nanorods, TiO2 coating, and subsequent deposition of Ag nanoparticles on their surface using AgNO3, enabling intimate interfacial contact among the different components. The prepared samples were characterized by XRD, HRTEM, XPS, and UV-Vis. The chemical composition of the composite Ag-CuO/TiO2 showed a Cu/Ti atomic ratio of 2.58, as well as a Ag/Cu ratio of 0.91. The UV-Vis spectrum reveals the largest absorption peak at 550 nm for the composite Ag-CuO/TiO2. The prepared Ag-CuO/TiO2 composites were applied to the visible-light degradation of tetracycline hydrochloride, with the photocatalytic degradation rate reaching 80.7% under the optimal conditions within 60 min, which is significantly better than CuO and CuO/TiO2 without silver nanoparticles. Capture experiments indicated that h+ are involved during the course of the photodegradation and that h+ are the main active substances. Furthermore, the proposed mechanism for the photodegradation of the Ag-CuO/TiO2 composites is given. It has potential applications in the treatment of organic pollutants in water.