Synthesis of Magnetic Fe3O4Modified Graphene Nanocomposite and its Application on the Adsorption of some Dyes from Aqueous Solution

Facile Sonochemical Synthesis of Flexible Fe-Based Metal-Organic Frameworks and Their Efficient Removal of Organic Contaminants from Aqueous Solutions

An iron-based metal-organic framework, MIL-53(Fe), was synthesized via the simple sonochemical method, which is a facial and fast strategy, and their adsorption performance for organic contaminants removal from aqueous solutions was studied. The crystal structure and morphology analysis indicate that the sonochemical synthesis of MIL-53(Fe) particles was faster than the solvothermal preparation method, showing high crystallinity with a downsized hexagonal bipyramid shape. Furthermore, the prepared MIL-53(Fe) exhibited enhanced adsorption capability for the organic dyes compared to metal-organic framework prepared via the solvothermal method and showed excellent maximum adsorption capability for the methyl orange removal from aqueous solutions. Based on the superior adsorption properties and facile synthesis, MIL-53(Fe) prepared by ultrasound irradiation has a potential application for an efficient, economic, and ecofriendly wastewater purification process.

Fabrication of Fe3O4/MgAl-layered double hydroxide magnetic composites for the effective removal of Orange II from wastewater

A facile approach has been developed to construct a composite of magnetic Fe₃O₄ (MNPs) and regular hexagon Mg-Al layered double hydroxide (MNPs/MgAl-LDH) via a two-step hydrothermal method combined with the urea hydrolysis reaction for the removal of Orange II. The scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy results showed MNPs and MgAl-LDH have been combined successfully, providing the combination of the superior properties of fast separation and high adsorption capacity. The pH values, contact time, initial dye concentration and temperature were investigated in detail. The kinetics and isotherm study showed the adsorption of Orange II on MNPs/MgAl-LDH obeyed the pseudo-second-order and Langmuir model respectively and the adsorption processes were spontaneous and endothermic in nature. Also, some coexisting anions such as Cl^-, NO₃ ^-, CO₃ ^- and SO₄ ^2- had no significant effect on the removal of Orange II. The mechanism study revealed that the adsorption of Orange II on MNPs/MgAl-LDH mainly involves surface adsorption through electrostatic force and the layer anion exchange. Moreover, Orange II could be desorbed from MNPs/MgAl-LDH using 100 mg L^-1 NaOH and used for four cycles without any adsorption performance loss, demonstrating MNPs/MgAl-LDH prepared in this work could be used as a cost-effective and efficient material for the removal of Orange II.