Complete photodegradation of tetracycline induced by surface microenvironment of graphitic carbon nitride/silver phosphate

Silver phosphate (Ag 3 PO 4 ) is a promising photocatalyst, but the photo-corrosion issue limits an effective and comprehensive photocatalysis degradation of tetracycline (TC). In this work, a unique graphitic carbon nitride-Ag 3 PO 4 (KCN-AP (40 %) ) core-shell structure was prepared via a simple chemical sedimentation method. The unique graphitic carbon nitride sheet encloses Ag 3 PO 4 to trap excited electrons from the conduction band position of Ag 3 PO 4 , suppressing the reduction of Ag + and Ag metal deposition on the surface of Ag 3 PO 4 . Under visible light irradiation, the optimized KCN-AP (40 %) can photodegrade nearby 100 % of TC within 20 min with a first-order kinetic constant of 0.127 min −1, which is 3.34 and 3.97-folds higher than those of Ag 3 PO 4 and graphitic carbon nitride, respectively. A series of factors that may affect photoactivity of KCN-AP (40 %) including pH, inorganic ions, and organic matter are investigated. In final, the photodegradation mechanisms and intermediates were proposed based on ex-situ HPLC-MS. This work explains the deep decomposition of TC and presents a facile approach for designing and manufacturing Ag 3 PO 4 based nanohybrids.