Fig 1.
The chemical structure diagram of CR.
Fig 2.
The SEM (A), TEM (B), XRD (C), EDS (D), and VSM (E) of magnetic Co0.5Mn0.5Fe2O4 nanoparticles calcined at 400°C for 2 h with 20 mL absolute ethanol.
Fig 3.
Adsorption kinetics curves of different initial CR concentrations.
Fig 4.
Effects of adsorption time and initial CR concentration (50 mg·L-1 (A), 100 mg·L-1 (B), 150 mg·L-1 (C), 200 mg·L-1 (D)) on the adsorption capacity of magnetic Co0.5Mn0.5Fe2O4 nanoparticles.
Table 1.
Fitted kinetics parameters for adsorptions of CR in aqueous solution onto magnetic Co0.5Mn0.5Fe2O4 nanoparticles at room temperature.
Fig 5.
Adsorption isotherms of CR onto magnetic Co0.5Mn0.5Fe2O4 nanoparticles at 303 K (A), 313 K (B), and 323 K (C).
Table 2.
The parameter values for Langmuir, Freundlich and Temkin models for CR onto magnetic Co0.5Mn0.5Fe2O4 nanoparticles at different temperatures (303 K, 313 K, 323 K).
Table 3.
Compared the maximum adsorption capacity of CR onto magnetic Co0.5Mn0.5Fe2O4 nanoparticles with other adsorbents.
Fig 6.
Plots of ln(qe/Ce) vs. qe (A) and linear van’t Hoff (B) for CR adsorbed onto magnetic Co0.5Mn0.5Fe2O4 nanoparticles at different temperatures.
Table 4.
Thermodynamic parameters of CR adsorbed onto magnetic Co0.5Mn0.5Fe2O4 nanoparticles.
Fig 7.
FTIR spectra of magnetic Co0.5Mn0.5Fe2O4 nanoparticles (a), CR (b), magnetic Co0.5Mn0.5Fe2O4 nanoparticles after adsorbing CR (c), magnetic Co0.5Mn0.5Fe2O4 nanoparticles after adsorbed re-calcined (d).
Fig 8.
Effect of ion strength (A), and pH (B) on the equilibrium adsorption capacity of CR on magnetic Co0.5Mn0.5Fe2O4 nanoparticles.
Fig 9.
The photographs of Fe3+ solution (A), Fe3+ solution driped NaSCN (B), CR solution (C), CR solution after adsorption (D), and CR solution afetr adsorption and driped NaSCN (E).
Fig 10.
The XRD patterns of fresh nanoparticles, spent nanoparticles and regeneration nanoparticles (A) and the recycling of magnetic Co0.5Mn0.5Fe2O4 nanoparticles (B).
Fig 11.
The CV curves (A) and EIS curves (B) of Bare MGCE (a), MGCE/Co0.5Mn0.5Fe2O4 (b), MGCE/Co0.5Mn0.5Fe2O4 /CR (c).