Novel magnetically separable ag@agcl-fe3 o4 /rgo nanocomposites for enhanced dielectric barrier discharge plasma reaction for high-performance water decontamination

Abstract

A magnetic nanocatalyst, Ag@AgCl-Fe3 O4 /RGO, was prepared and used with dielectric barrier discharge plasma (DBD) to treat wastewater containing reactive black 5 azodye. Magnetic Fe3 O4 and AgCl nanoparticles were successively loaded on reduced graphene oxide by hydrother-mal and deposition–precipitation method, which was produced by restoring the graphene oxide. Ag nanoparticles were then photo-reduced on the surface of AgCl. The as-prepared nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, Raman, and vibrating sample magnetometer analysis. Response surface methodology was used to optimize the preparation process of Ag@AgCl-Fe3 O4 /RGO nanoparticles and the decolorization of Reactive Black 5 in DBD-Ag@ AgCl-Fe3 O4 /RGO combined system. The best material preparation conditions were that the dosage of Fe3 O4 /RGO, AgNO3, NaCl, and the UV light reduction time are 110 mg, 0.23 g, 47 mg, and 1.1 h, respectively. The decolorization rate was measured by the absorbance before and after treatment, and the effects of the initial concentration, pH, conductivity, discharge current, and sodium dodecyl sulfonate concentration (SDS) in the dye solution were studied. The results showed that the optimum conditions for maximum Reactive Black 5 decolorization efficiency (99.3%) in the system of DBD-Ag@AgCl-Fe3 O4 /RGO were pH of 2, the concentration of 20 mg/L, the conductivity of 100 μS/ cm, and do not add SDS, which was better than that of 88.6% in DBD alone. Meanwhile, the synthesis mechanism of Ag@AgCl-Fe3 O4 /RGO and the reaction mechanism of DBD-Ag@AgCl-Fe3 O4 /RGO were discussed. The morphology and repetition usage-ratio of the nanocatalyst was also studied during the treatment.