Dual 3D Structural Bi2WO6@Graphene Hydrogel Composites Modified Molecularly Imprinted Polymers: Application for Sensitive Photoelectrochemical Sensing of 4-Nitrophenol in PM2.5

The accurate measurement of nitrophenols (NPs) in fine particulate matter (PM 2.5 ) is critical because NPs are identified as the main constituents of brown carbon in PM 2.5 , which influence the global radiative forcing and regional climate. Herein, we presented a specific and ultrasensitive photoelectrochemical (PEC) sensor (MIPs/Bi 2 WO 6 @GH/ITO) for 4-nitrophenol (4NP) detection by electrodepositing molecularly imprinted polymers (MIPs) polypyrrole on indium tin oxide coated glass (ITO) electrode modified with dual 3D structural Bi 2 WO 6 @graphene hydrogel (GH) composites. The composites were successfully synthesized through the simple one-step hydrothermal method with 3D flower-like Bi 2 WO 6 efficiently distributed on the 3D porous networks of GH. Under optimum conditions, the PEC sensor exhibited a wide linear range of 5.0 × 10 −12 –1.0 × 10 −7 M for 4NP with a low detection limit of 5.78 × 10 −13 M. MIPs/Bi 2 WO 6 @GH/ITO was further successfully applied for 4NP assay in PM 2.5 . The results indicated that the developed PEC sensor had broad applications for NPs detection in the environmental fields.