Preparation Of Ce ^{3 +} Doped Zn Ferrite Magnetic Nanomaterials And Application Of Sewage Treatment

A solvothermal synthetic route was used to prepare Ce3+doped Zn ferrites, where sphere-like clusters aggregated by nanosized particles were fabricated. The size of the cluster and the saturation magnetization of the sample are decreasing with the increase of Ce3+. These samples can be easily separated from aqueous solutions by applying a magnetic field and have a high loading capacity of Cr(â…¥). The Cr(â…¥) adsorption experiments indicated that the adsorption was divided into two processes, in which the first one took place about6h, the second one took place between6and96h. The maximum adsorption capacity for Cr(â…¥) was determined to be57.24mg/g. Langmuir model was employed to fit the adsorption isotherm, which implied the single layer adsorption. The data of SBET, external area and porous area of the samples can be used to explain these adsorption processes. And the Ce3+ions doped in the sample induced the increasing adsorption capacity of Cr(â…¥). The adsorption process can be described by the pseudo-second-order kinetic model.Monodisperse Ce3+doped zinc ferrite magnetic nanoparticles (MNPs) were fabricated without any surfactant by a solvothermal route. The surface area of the MNPs is higher than the clusters aggregated by nanoparticles previously reported in our laboratory. A reaction mechanism was proposed. First, a-(Fe, Zn)OOH and CeFeO3were formed. Second, a-Fe2O3was fabricated through transformation of the a-(Fe, Zn)OOH. Third, Fe2+was fabricated by the reaction between Fe3+and ethylene glycol, Ce3+doped zinc ferrite were prepared at the same time, and the CeFeO3was dissolved. The formation of Fe2+may be the key step for the fabrication of the ferrite. Fourth, CeFeO3was again obtained, and the replacement between Zn2+and Fe2+may occur between the solution and the ferrite structure. Adsorption experiments of Congo red (CR) onto the as-prepared MNPs showed that the maximum adsorption capacity was72.15mg/g. Langmuir model was employed to fit the adsorption isotherm, which implied the single layer adsorption. The pseudo-second-order kinetic model can be used to describe the adsorption processes.Sandwich-structured ZnCe0.03Fe1.9704@nSiO2@SBA-15(mSBA-15A) was fabricated in the present conditions. The sample showed a rod-like shape with uniform mesochannels. The pore size, pore volume and surface area of the sample were determined to be about5.4nm,0.53cm3/g, and481m2/g, respectively. The mSBA-15A is more suitable as an adsorbent for wastewater treatment. And it can be used as an adsorbent in acidic solution, such as1.0mol/L HC1aqueous solution. The maximum adsorption capacity for methylene blue (MB) was determined to be241mg/g, which is higher than some references reported. Langmuir model was employed to fit the adsorption isotherm, which implied the single layer adsorption. The adsorption process can be described by the pseudo-second-order model.