RESUMEN
Herein, the preparation of numerous bismuth oxychloride/bismuth oxybromide/bismuth oxyiodide/graphene oxide (BiOxCly/BiOmBrn/BiOpIq/GO) composites is reported. A facile hydrothermal method was employed to synthesize these photocatalysts, which had various GO contents. A total of 10 bismuth-oxyhalide composites were isolated and characterized using FE-SEM, XRD, FE-TEM, UV-Vis-DRS, FT-IR, EPR, HR-XPS, PL, and BET. The photocatalytic efficiencies of these 10 bismuth-oxyhalide composites were measured under visible-light irradiation by estimating the concentration of 2-hydroxybenzoic acid (HBA) degradation. The findings indicated that the rate constant order of the HBA degradations was BiOCl/BiOBr/BiOI/GOâ¯>â¯Bi3O4Cl/Bi3O4Br/Bi4O5I2/GOâ¯>â¯Bi12O17Cl2/Bi3O4Cl/Bi12O17Br2/ Bi7O9I3/GOâ¯>â¯Bi12O17Cl2/BiOBr/BiOI/GOâ¯>â¯Bi12O17Cl2/Bi12O17Br2/Bi7O9I3/Bi5O7I/GOâ¯>â¯Bi3O4Cl/BiOBr/Bi3O4Br/Bi4O5I2â¯>â¯Bi3O4Cl/BiOBr/BiOIâ¯>â¯BiOCl/BiOBr/BiOIâ¯>â¯Bi12O17Cl2/Bi5O7Br/Bi5O7Iâ¯>â¯GO. A maximum rate constant of 0.191â¯h-1 was reached for BiOCl/BiOBr/BiOI/GO, providing photocatalytic efficiency that was eight times higher than that of composite BiOCl/BiOBr/BiOI. We also proposed a photocatalytic mechanism demonstrating that O2-, h±, OH, and 1O2 are all essential for HBA degradation.
RESUMEN
This is the first paper to report a series of bismuth oxyfluoride/bismuth oxyiodide (BiOpFq/BiOxIy) nanocomposites with different F/I molar ratios, pH values, and reaction temperatures that were synthesized through a template-free and controlled hydrothermal method. These nanocomposites were characterized through scanning electron microscope energy dispersive microscopy (SEM-EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), and diffuse reflectance spectroscopy (DRS). Under visible-light irradiation, the BiOpFq/BiOxIy composites exhibited excellent photocatalytic activities in the degradation of crystal violet (CV) and 2-hydroxybenzoic acid (HBA). The order of rate constants was BiOF/BiOIâ¯>â¯BiOIâ¯â«â¯BiOF. The photocatalytic activity of BiOF/BiOI composites reached a maximum rate constant of 0.2305â¯h-1, 1.2 times higher than that of BiOI and 100 times higher than that of BiOF. Thus, the derived BiOF/BiOI is crucial for photocatalytic activity enhancement. After the removal of CV in the third cycle, no apparent deficits in photocatalytic activity were observed, and the observed deficit was 8.2% during the fifth run. Overall, the catalytic activity and stability observed for the proposed composites were determined to be adequate under visible-light irradiation. For various scavengers, the noted quenching effects demonstrated that reactive O2- has a notable role in the degradation of the applied CV.