Visible light photodegradation of 4-nitrophenol by new high-performance and easy recoverable Fe3O4/Ag2O-LDH hybrid photocatalysts

Till now, water contaminant photodegradation has been the most influential method to remove low but dangerous concentrations of pollutants. Herein, a green method was employed to enhance the photocatalytic activity of ZnAl-LDH through depositing Ag and magnetite nanoparticles on the surface of layered double hydroxide (LDH) sheets. The structural and electrochemical characterization of as-prepared Zn3Al-CO3 (ZA-LDH) and Fe3O4/Ag2O-LDH (M(10)A(5)-LDH) composite was determined by X-ray diffraction (XRD) analysis, Brunauer-Emmett-Teller (BET) theory, field emission scanning electron microscopy (FESEM) along with energy-dispersive X-ray spectroscopy (EDX) mapping, UV-vis diffuse reflectance spectra, photoluminescence spectra, and transient photocurrent response. All of the analyses confirmed the photo-response enhancement of the M(10)A(5)-LDH compared with virgin LDH. The mineralization of p-nitrophenol (PNP) under visible light revealed that the photodegradation rate of composite (0.02 min(-1)) is fourfold more significant than that of the bare ZA-LDH (0.005 min(-1)). The active radical capturing tests exhibited that h(+), center dot OH, and center dot O-2(-) play substantial roles in PNP degradation, respectively. The potential photodegradation mechanism involves the charge transfer from Fe3O4 and Ag2O to LDH, producing active radicals for the degradation process.