Synthesis of Z-scheme g-C3N4 nanosheets/Ag3PO4 photocatalysts with enhanced visible-light photocatalytic performance for the degradation of tetracycline and dye

Graphene-like C3N4/Ag3PO4 photocatalysts are synthesized by calcination and solutions precipitating method. The obtained g-C3N4/Ag3PO4 composites display excellent photocatalytic activity for the degradation of methylene orange (MO), rhodamine B (RhB) and tetracycline (TC) under visible light irradiation. The solutions containing RhB (10 mg/L) and MO (10 mg/L) can be efficiently degraded within 15 min and 30 min. Especially, nearly 80% of TC (50 mg/L) is degraded within 20 min, which are much better than those of pure g-C3N4 nanosheets and Ag3PO4, implying that strong interaction and reasonable energy band alignment in the contact interface can effectively transfer the carries. Furthermore, the g-C3N4/Ag3PO4 composites exhibit the improved stability, and only a slight decrease is observed after three recycling runs. Moreover, the impact of inorganic ions and PH values on the degradation performance is rather small. The Z-scheme photocatalytic mechanism of the g-C3N4/Ag3PO4 composites based on the active species trapping experimental is proposed. This work demonstrates the promising applications of the g-C3N4/Ag3PO4 composites in environmental issues. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.