Photocatalytic detoxification of hazardous pymetrozine pesticide over two-dimensional covalent-organic frameworks coupling with Ag3PO4 nanospheres

A Z-scheme Ag3PO4/TpPa-1-COF heterojunction was constructed by coupling 2D π-π stacking covalent organic framework (COF) with Ag3PO4 nanospheres. It exhibited excellent photocatalytic activity on degradation of pesticide pymetrozine (PYM) and Rhodamine B (Rh. B) under simulated solar irradiation (>420 nm). The highest degradation rate (99.3% and 96.7%) of PYM and Rh. B were achieved over as-prepared Ag3PO4/TpPa-1-COF (weight ratio 1:1) heterojunction, which is greatly higher than those of pristine COF and Ag3PO4. Simultaneously, the acute toxicity evaluation verified the property of efficiently detoxing the hazardous pesticide. Furthermore, the possible pathway for degrading pymetrozine was predicated by the practical confirmation of intermediates. The enhancement of photocatalytic performance for Ag3PO4/TpPa-1-COF composites is attributed to the structure of Z-scheme heterojunction between Ag3PO4 and COF.