Novel highly stable β-cyclodextrin fullerene mixed valent Fe-metal framework for quick Fenton degradation of alizarin

Abstract

b-Cyclodextrin (b-CD) supported magnetic nanoscaled fullerene/Fe 3 O 4 (CDFMNPs) and fullerene/Fe 3 O 4 (FMNPs) composites were prepared and characterized. These composites can be utilized as heterogeneous catalysts for the Fenton oxidation reaction to degrade alizarin in aqueous solutions. The saturation magnetization (M s ) value of quasi-spherical CDFMNPs was found to be 13.16 emu g À1 and their diameter was in the range of 25-30 nm. The catalytic activities of the prepared materials were tested with varying conditions of pH, amount used and the concentration of H 2 O 2 for degradation of alizarin at room temperature. The exceptionally high degradation efficiency of CDFMNPs was observed for alizarin at pH 3 with 2.0 g L À1 catalyst and 25 mM of H 2 O 2 . The increased oxidative degradation efficiency is attributed mainly to the formation of active hydroxyl radicals (cOH) on the surface of the catalyst, which are generated by the active decomposition of H 2 O 2 by the solid heterogeneous catalyst and the promoting effect of b-CD. CDFMNPs can be magnetically separated and the catalyst was found to be reusable and stable for five successive runs with no significant loss of catalytic activity. In the magnetic environment of Fe 3 O 4 nanoparticles, fullerene has a crucial role to enhance the activity by increasing the stability with nominal iron leaching. Based on mass analysis of alizarin degradation, the formation of aliphatic acids and monocyclic compounds through phthalic anhydride and di-methyl phthalate established the proposed degradation path.

Improvement of H2O2 Utilization by the Persistent Heterogeneous Fenton Reaction with the Fe3O4-Zeolite-Cyclodextrin Composite

“…Importantly, a phenomenon may be noted from Figure c, showing that the homogeneous Fenton reaction conduces continuously even after 240 min in a strongly acidic condition. This result indicates that F-Z-C shows good stability and the functional substances (mainly cyclodextrin) on the material are not destroyed; this conjecture can also be confirmed in previous studies. , …”

“…This result indicates that F-Z-C shows good stability and the functional substances (mainly cyclodextrin) on the material are not destroyed; this conjecture can also be confirmed in previous studies. 45,46 3.4. Concluded Mechanism of the F-Z-C Heterogeneous Fenton Reaction.…”

Synthetic Application of Cyclodextrins in Combination with Metal Ions, Complexes, and Metal Particles

“…Good stability was found in five repeated runs. In a related study, fullerene/Fe 3 O 4 particles were coated with βCD (spherical particles of 25–30 nm) [203] . Catalyst features in the degradation of alizarin (entry 4), including total iron ion dissolution of 7 mg L −1 , are similar to those given in entry 3.…”

Radical scavenger competition of alizarin and curcumin: a mechanistic DFT study on antioxidant activity

“…Note that • OH can interact with AR in different positions, i.e., can get close to AR from many directions, e.g., perpendicular to the aromatic ring; therefore, an adduct formation can be also an option for a radical scavenger. It is worth mentioning that under specific conditions, the complete degradation of alizarin could be detected, and the role of hydroxyl radical was taken into account in the proposed mechanisms [ 49 , 50 ].…”

“…In most computational studies about radical scavengers and their reactions to free radicals, the type of radical formation has been discussed; however, we have found that there is a lack of knowledge about the adduct formation of these well-investigated compounds [45][46][47][48]. It is worth mentioning that the degradation of alizarin has been also studied experimentally but only a few mechanistic studies could be found under specific conditions resulting in completely decomposed structures [49,50].…”