We designed and prepared the nanoscale Fe2O3/KIT-6 mesoporous structure catalysts for heterogeneous Fenton degradation of methylene blue using the isometric impregnation method. The particle size, mesoporous ordering, specific surface area and pore size distribution were characterized by the transmission electron microscope, scanning electron microscope, small angle X-ray diffraction and nitrogen adsorption-desorption analysis. The results show that the nanoscale Fe2O3 are evenly distributed in the KIT-6 mesopores, and the Fe2O3/KIT-6 catalysts with 10 wt% of Fe content have the optimal Fenton catalytic performance. This is because the proper amount of nanoscale Fe2O3 with the larger specific surface area and more active reaction sites will supply effective catalytic mass transfer channel, reduce the aggregation of the pure nanoscale particles during the catalysis, and ultimately improve the Fenton catalytic degradation performance.

Selective leaching of Mg in Mg modified mesoporous hematite promotes highly efficient wet peroxide oxidation of methylene blue.

A highly porous Fe2O3/KIT-6 with Mg substitution (MgO@Fe2O3/KIT-6) has been synthesized through a coincipient wetness impregnation of Fe and Mg into ordered mesoporous KIT-6 silica. The postreactio...

A novel mesoporous Fe/KIT-6 catalyst was prepared by simple wetness impregnation technique. The impregnation of metal species did not alter the well-ordered three-dimensional cubic Ia3d mesostructure of KIT-6. This novel impregnated Fe/KIT-6 catalyst showed high degradation efficiency for methylene blue. The effects of catalyst loadings, pH, Fe content and H2O2 dosage were investigated. At neutral pH, 2600 mg L-1 of H2O2 dosage and initial 30 mg L-1 of methylene blue concentration, over 90% methylene blue degraded in 80 minutes with 15 wt-% Fe/KIT-6. With increasing of Fe loading from 5 to 20 wt-%, degradation efficiency decreased after increasing. The reason may lie in the confinement of nanoparticles inside micropores or mesopores with high Fe content. The degradation of methylene blue might be due to the heterogeneous Fenton oxidation of Fe/KIT-6 catalyst and homogeneous Fenton of leached iron ions from the catalyst.

An environmentally compatible and size-controlled method has been employed for synthesis of superparamagnetic magnetite nanoparticles with prehydrolysate from corn stover. Various characterizations involving X-ray diffraction (XRD), standard and high-resolution transmission electron microscopy (TEM and HRTEM), selected area electron diffraction (SAED), and thermogravimetric analysis (TGA) have integrally confirmed the formation of magnetite nanoparticles with homogeneous morphology and the formation mechanism of magnetite only from ferric precursor. Organic materials in the prehydrolysate act as a bifunctional agent: (1) a reducing agent to reduce ferric ions to prepare magnetite with the coexistence of ferric and ferrous ions; and (2) a coating agent to prevent particle growth and agglomeration and to promote the formation of nanoscale and superparamagnetic magnetite. The size of the magnetite nanoparticles can be easily controlled by tailoring the reducing sugar concentration, reaction time, or hydrothermal temperature.