Ultrafast photocatalytic degradation of nitenpyram by 2D ultrathin Bi2WO6: mechanism, pathways and environmental factors

As a common insecticide, nitenpyram (NTP) seriously threatens the human health and environmental safety. In this work, a visible-light-responsive photocatalyst two-dimensional (2D) Bi2WO6 was synthesized and applied to degrade NTP. Compared with bulk Bi2WO6, the 2D Bi2WO6 exhibits better photocatalytic performance for NTP degradation under visible-light irradiation. The enhanced activity can be ascribed to the unique 2D structure which would induce to higher efficiency of carrier separation. Moreover, hole (h+) plays a major role (and ·O2−) in the degradation of NTP. Based on the intermediates detected by high-performance liquid chromatography–mass spectrometry (HPLC–MS), the degradation pathway of NTP was proposed. In addition, the influence of typical environmental factors (pH, water matrix, inorganic cations and common anions) on the degradation of NTP was also investigated. This work not only helps people to understand the degradation of pesticides in actual water bodies, but also provides reference for the subsequent treatment of agricultural wastewater.Graphical abstract