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

Abstract

AbstractTwo Fenton‐like catalysts of iron oxide (Fe2O3) or Fe2O3 doped with silver oxide (Ag2O) and supported on acidified multi‐walled carbon nanotubes (a‐MWCNTs) were successfully prepared by wet impregnation and calcined at 200 °C and noted as Fe2O3/MWCNTs and Ag2O‐Fe2O3/MWCNTs, respectively. These samples were characterized using techniques such as TEM, FTIR, N2 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 Ag2O‐Fe2O3/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 Ag2O with Fe2O3 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 Fe2O3/MWCNTs catalyst increased by about 10% after loading ~1wt.% of Ag2O. The catalytic performance was considerably based on pH of solution, H2O2 concentration, and dye concentration. The reusability tests confirmed that Ag2O‐Fe2O3/MWCNTs nanocomposite offers high stability over three consecutive cycles, where over 90% degradation of MR dye was obtained. Finally, Ag2O‐Fe2O3/MWCNTs nanocomposite showed excellent Fenton catalytic oxidation and reusability as compared with Fe2O3/MWCNTs composite in Fenton‐like processes.