| Abstrakt: |
In the current study novel magnetic BiOBr-Gd3+doped CoFe2O4heterojunction nanocomposites fabricated by chemical precipitation method for Acid Violet 7 (AV 7) and Reactive Red 120 (RR 120) dye degradation under sunlight are presented. The samples were well characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), UV-visible near infrared (NIR), photoluminescence (PL), TRF, EIS, Mott–Schottky, and BET analysis. X-ray diffractograms of BiOBr-Gd3+doped CoFe2O4nanocomposites authenticate the formation of the composite composed of diffraction peaks of both BiOBr and Gd3+doped CoFe2O4samples. Photoluminescence (PL), Time Resove Fluorescence spectrocopy (TRF) and Electrochemical Impedance Spectroscopy (EIS) investigations were explored to examine the transfer efficiency of photoinduced charge carriers. Among the synthesized materials, the BiOBr-Gd3+doped CoFe2O4-2 nanocomposite presents superior degradation capability for RR 120 of 87.34% and AV 7 dyes of 98.41%. The apparent rate constant (k) value of 0.1317 min−1for AV 7 is sixteen times higher and RR 120 (0.0135 min−1) is 2 times higher than pristine BiOBr. The radical trapping experiments also proved the role of photogenerated h+, O2∙−, and ∙OH radicals in the degradation mechanism. The superior performance of BiOBr-Gd3+doped CoFe2O4-2 is ascribed to the formation of the heterostructure, the in-built electric field, and energy-band alignment, which thermodynamically and kinetically favors the photoactivity and stability of the heterojunction. |
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