Sonocatalytic degradation of organic dye pollutants from aqueous solutions using MIL-۱۰۱ (Cr)/CuO/MgFe۲O۴ heterojunction nanocatalyst

In this study, a novel magnetic MIL-۱۰۱(Cr)/CuO/MgFe۲O۴ nanocomposite catalyst was successfully fabricated by the hydrothermal route for the sonodegradation of organic dye pollutants from aqueous solutions. The structural, morphological and magnetic features of the nanocomposite were characterized by means of XRD, FESEM, EDS, VSM and BET analyses. To investigate the sonocatalytic performance of the as-manufactured MIL-۱۰۱(Cr)/CuO/MgFe۲O۴ nanocomposite, the H۲O۲-assisted degradation of organic dyes like methylene blue (MB), Rhodamine B (RhB) and methyl orange (MO) in aqueous solution were studied under ultrasound irradiation. The gained results illustrated that the ternary MIL-۱۰۱(Cr)/CuO/MgFe۲O۴nanocomposite had better activity for sonodegradation of these dyes than MIL-۱۰۱(Cr)/MgFe۲O۴, bare MIL-۱۰۱(Cr), CuO or MgFe۲O۴. The enhanced sonocatalytic activity of the synthesized nanocomposite could be related to the fast generation and separation of electrons and holes in MgFe۲O۴, CuO and MIL-۱۰۱(Cr). Plus, the relatively high specific surface area of the MIL-۱۰۱(Cr)/CuO/MgFe۲O۴ and magnetic feature of MgFe۲O۴ improve the degradation yield of the organic dyes. The separation of the magnetic sonocatalyst from aqueous solutions could be easily achieved applying an external magnetic field. The several parameters on the sonocatalytic activity, including irradiation time, dye type, catalyst amount and initial dye concentration were also evaluated. The trapping experiments displayed that .OH free radicals are the significant reactive species in the dye degradation. Additionally, the recyclability experiment, was also implemented to ensure the stability of the used sonocatalyst.

Keywords:

MIL-۱۰۱ (Cr)/CuO/MgFe۲O۴ , nanocomposite , sonocatalyst , organic dyes