Study on the adsorption/degradation of Rhodamine B by Fenton-like reagent based on carbon nanotubes

In this work, Rhodamine B (RhB) dye was catalytically degraded by using Fenton-like reagent (CNIQ), which was made by self-made multiwalled carbon nanotubes (MWNTs) supported iron oxide FexOy (MWNTs-FexOy) and H2O2. The MWNTs-FexOy was characterized by transmission electron microscope (TEM), energy dispersive spectrometer (EDS), Fourier transform infrared spectroscopy (FT-IR), Brunauer, Emmett, and Teller (BET), and X-ray photoelectron spectroscopy(XPS). The factors affecting the degradation of RhBs include the pH value, the reaction temperature, the dosage of MWNTS-FexOy, the dosage of H2O2, the treatment methods, and the concentration of RhB were investigated. Based on the TEM, EDS, FT-IR, BET, and XPS analysis, iron oxide was successfully loaded on carbon nanotubes. The RhB removal rate could reach to 100% under the optimal conditions: the solid to liquid ratio is 1:2, the amount of H2O2 (30%) is 0.1 mL, pH is 3.58, and oscillating time is 60 min. The results also show that the adsorption kinetic of RhB onto MWNTS-FexOy belongs to the pseudo-second-order kinetics. The activation energy and adsorption rate constant are 21.76 kJ/mol and 0.00047 g/(mg min), respectively, the degradation rate increases with the temperature increasing. From this study, we conclude that CNIQ has better adsorption/degradation effect for dye RhB, and it can be used widely in water treatment of textile industry.