Simultaneous and fast degradation of methylene blue, methylene orange, and Rhodamine B dyes by high-performance rGO/Fe3O4/ZnSe magnetic nanocomposites

Abstract

Dark catalyst materials are a new generation of catalyst material for the removal of dye and pigment molecules from water and wastewater. In this research, reduced graphene oxide (rGO)/Fe3O4/ZnSe magnetic nanocomposites were used as dark catalyst nanomaterial for ultrafast degradation of methylene blue (MB), Rhodamine B (RB), and methylene orange (MO) dyes in darkness. The obtained results showed that rGO/Fe3O4/ZnSe nanocomposite had excellent dark catalyst ability and could completely remove MB, RB, and MO dyes from water. Also, rGO/Fe3O4/ZnSe nanocomposite degraded these dyes simultaneously in 4 min stirring in the darkness. The obtained results showed that the degradation process was independent to the pH of the effluent. RGO/Fe3O4/ZnSe magnetic nanocomposite was synthesized by a refluxing method. The prepared magnetic nanocomposites were characterized by different analyses such as XRD, FT-IR, Raman, TEM, FESEM, Zeta, EDS, and VSM. The XRD analysis and TEM images confirmed the successful formation of ZnSe and Fe3O4 on GO nanosheets. VSM analysis results showed that rGO/Fe3O4/ZnSe nanocomposites had good superparamagnetic behavior with magnetization saturation (Ms) at about 35.2 emu/g. The double layer capacitance (Cdl) and activated surface area of rGO/Fe3O4/ZnSe nanocomposite were measured at about 39 mF.cm−2 and 0.097 cm2, respectively.