Multi‐walled carbon nanotubes supported amorphous Fe₂O₃ and Ag₂O–Fe₂O₃ as Fenton catalysts for degradation of maxilon red dye

Abstract

Two Fenton-like catalysts of iron oxide (Fe 2 O 3 ) or Fe 2 O 3 doped with silver oxide (Ag 2 O) and supported on acidified multi-walled carbon nanotubes (a-MWCNTs) were successfully prepared by wet impregnation and calcined at 200°C and noted as Fe 2 O 3 /MWCNTs and Ag 2 O-Fe 2 O 3 /MWCNTs, respectively. These samples were characterized using techniques such as TEM, FTIR, N 2 adsorption at -196°C, and XRD. Their catalytic performances were determined through Fenton oxidation process of maxilon red dye (MR) at 25°C. Fenton degradation results disclosed that the Ag 2 O-Fe 2 O 3 /MWCNTs nanocomposite has the superior and the faster catalytic degradation rate of dye. This result was due to the synergistic effect that established from the combination of tiny amount of Ag 2 O with Fe 2 O 3 over a-MWCNTs support, which prevents the agglomeration of catalyst nanoparticles and enhances the adsorption of dye molecules. A full degradation of dye was obtained within 10 min at 25°C and the Fenton oxidation capability of Fe 2 O 3 / MWCNTs catalyst increased by about 10% after loading~1wt.% of Ag 2 O. The catalytic performance was considerably based on pH of solution, H 2 O 2 concentration, and dye concentration. The reusability tests confirmed that Ag 2 O-Fe 2 O 3 / MWCNTs nanocomposite offers high stability over three consecutive cycles, where over 90% degradation of MR dye was obtained. Finally, Ag 2 O-Fe 2 O 3 / MWCNTs nanocomposite showed excellent Fenton catalytic oxidation and reusability as compared with Fe 2 O 3 /MWCNTs composite in Fenton-like processes.

Potassium Ferrite as Heterogeneous Photo-Fenton Catalyst for Highly Efficient Dye Degradation

“…Catalysts 2020, 10, 293 2 of 12 α-FeOOH, and β-Fe2O3, have been used to catalyse or degrade various kinds of dye molecules due to their good photocatalytic activity, stable structure, and narrow band gap [10][11][12][13][14]. The catalytic activity of metal oxides is closely related to the crystal orientation, crystallinity, nanostructure, morphology, particle size, and surface properties of the material [15][16][17][18][19][20].…”

“…To overcome these drawbacks, one potential strategy is using heterogeneous photo-Fenton catalysts to degrade dye contaminants. So far, several iron oxides and iron hydroxides utilised as photo-Fenton catalysts, such as Fe 3 O 4 , α-Fe 2 O 3 , α-FeOOH, and β-Fe 2 O 3 , have been used to catalyse or degrade various kinds of dye molecules due to their good photocatalytic activity, stable structure, and narrow band gap [10][11][12][13][14]. The catalytic activity of metal oxides is closely related to the crystal orientation, crystallinity, nanostructure, morphology, particle size, and surface properties of the material [15][16][17][18][19][20].…”

The Removal of Binary Mixture of Dyes by Heterogeneous Fenton Oxidation: Kinetics, Product Identification and Toxicity Assessment

“…The peak at 604 cm -1 is assigned to Fe-O stretching band indicating the presence of Fe 2 O 3 , that at 3446 cm -1 to the characteristic stretching vibrations of -OH moieties probably belonging to the adsorbed water molecules on the surface during the preparation process of the catalyst and that at 1647 cm -1 to H-OH bending vibrations at γ-Fe 2 O 3 surface. [28][29][30] The weight (%) of iron and oxygen on the surface of n-Fe 2 O 3 as analysed by EDX, was found to be 83.71 and 16.29%, respectively (Fig. 3).…”

Cationic Dye Degradation and Real Textile Wastewater Treatment by Heterogeneous Photo-Fenton, Using a Novel Natural Catalyst

“…Another approach has been established with the utilization of solid phase (photo) catalysts (heterogeneous photo-Fenton). In the photocatalytic degradation of dyes, many iron oxides have been investigated in previous studies, regarding their impressive photocatalytic activity, structural stability, and narrow band gap, such as magnetite, goethite, and hematite [15]. However, most of the works available in the scientific literature only investigated the effect of the process on dye aqueous solutions [16], not taking into account the interference of other substances (such as dissolved organic matter), typically occurring in real wastewater.…”