Construction of ternary Ag/AgBr@UIO-66(NH2) heterojunctions with enhanced photocatalytic performance for the degradation of methyl orange.

Metal-organic frameworks (MOFs) have been attracting considerable attention and present a great potential in photocatalytic water treatment, paving the way for building efficient and environmentally-friendly photocatalysts. In this work, a stable photoactive UIO-66(NH₂) incorporated with Ag/AgBr photocatalyst has been successfully fabricated through the sonication-assisted deposition-precipitation technique and exhibits remarkable photocatalytic activity for the degradation of methyl orange (MO) dye under visible light irradiation (λ ≥ 420 nm). The as-prepared photocatalysts are characterized by powder X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, BET, X-ray photoelectron spectra, UV-vis diffuse reflectance spectra, and photoluminescence spectra. Moreover, the obtained Ag/AgBr@UIO-66(NH₂) photocatalyst shows an outstanding recyclability. The enhanced photocatalytic performance is attributed to the favorable band alignment between UIO-66(NH₂) and AgBr mediated by Ag NPs. The surface plasmon resonance (SPR) effect of Ag NPs make the electrons in Ag NPs preferentially transfer to AgBr, which facilitates the charge transfer of Ag/AgBr@UIO-66(NH₂). [ABSTRACT FROM AUTHOR]