Synthesis Of Cu/Mn/Fe/MoS₂ Nanocomposites For Degradation Application

Recently, multiple functionalization magnetic hybrid nanomaterials already become an important research subject. Moreover, Binary metallic oxide magnetic nanocomposites are a sort of significant inorganic functional materials which has special properties. These nanocomposites have attracted great attention in organic catalysis, biological molecules of magnetic separation, magnetic resonance imaging?MRI?, drug-loaded, enzyme reaction, and environmental protection. The study of this thesis is focused on the synthesis of binary metallic oxide magnetic nanocomposites, the controllable of size and shape, and degradation of methylene blue?MB?, three chapters research works are as followed:1. Monodisperse CuFe₂O₄ NPs have been successfully synthesized by using acetylacetone iron?III? and acetyl acetone copper?II? in oil amine and diphenyl ether system. To render these nanoparticles hydrophilic, the PEG-3,4-dihydroxy benzyl amine?DIB-PEG-NH₂? is grafted onto the as-prepared CuFe₂O₄ NPs via ligand exchange. And CuFe₂O₄-DIB-PEG-NH₂ was adopted for the degradation of dyes in the aqueous solution as catalyst. Interestingly, they not only exhibit high catalytic activity for rapid degradation MB dye, but also realize the fast selective degradation of MB dye from the mixed dye-wastewater: methylene blue?MB? and methylene orange?MO?, methylene blue?MB? and rhodamine B?RB?, methylene blue?MB? and rhodamine 6G?R6G? as is expected. More importantly, the CuFe₂O₄ nanocatalyst has a very low leaching loss and excellent reusability for ten catalysis cycles in the degradation of MB, indicating that CuFe₂O₄ nanocatalyst could overcome the drawbacks of homogeneous catalysts. Since the current method is simple and flexible to create recyclable catalyst with high stability and excellent selectivity toward dye degradation, this nanocatalyst is an important tool in catalysis, and the selective degradation and recycling of raw material in wastewater.2. Monodisperse MnFe₂O₄ NPs have been successfully synthesized by using acetylacetone iron?III? and acetyl acetone manganese?II? in oleic system, MnFe₂O₄ NPs with spherical, plate-like shapes and cubic can be prepared by simply tuning the amount of acetylacetone iron?III? and acetyl acetone manganese?II? and temperature. We have demonstrated that three MnFe₂O₄ NPs with different size and shape exhibit different levels of catalytic activity towards degradation of four organic dyes in the order of 4 nm?spherical? > 18 nm?platelike? > 27 nm?near-cubic?, this order was closely related to their surface-to-volume ratio and atom arrangements. Moreover, MnFe₂O₄ nanocatalysts possessed good sustainability even after 10 cycles of MB degradation, and furthermore the conversion of the catalysts was nearly unaffected. All these features suggest that selective fabrication of stable nanocatalysts with different size and shape is very important to harness their catalytic activities for environment remediation applications. 3. Core-shell MnFe₂O₄-DIB-PEG-NH₂@MoS₂ have been successfully synthesized by using MnFe₂O₄-DIB-PEG-NH₂ and MoS₂ through hydrothermal method, a series of experiment have been studied to confirm the influence of size- and shape- dependent MnFe₂O₄-DIB-PEG-NH₂@MoS₂ by using different concentration of thioacetamide, ammonium molybdate and MnFe₂O₄-DIB-PEG-NH₂. Meanwhile, we chose spherical, loose and porous of MnFe₂O₄-DIB-PEG-NH₂@MoS₂ to do adsorption experiment. MnFe₂O₄-DIB-PEG-NH₂@MoS₂ exhibit high adsorption activity for rapid degradation MB dye in 39 minutes and the maximum absorbing capability is 142.77 mg g-1. Furthermore, MnFe₂O₄-DIB-PEG-NH₂@MoS₂ realize the fast selective adsorption of MB dye from the mixed dye-wastewater?MB and MO, MB and R6 G, MB and RB? as is expected. All these features suggest that the properties of MnFe₂O₄-DIB-PEG-NH₂@MoS₂ have significant influence for environment remediation applications.