Self-assembled Fe₃O₄-layered double hydroxide colloidal nanohybrids with excellent performance for treatment of organic dyes in water

Abstract

We report a remarkably simple and efficient method for the preparation of colloidal nanohybrids consisting of Fe 3 O 4 nanoparticles and nitrate-containing MgAl-layered double hydroxide (LDH) nanocrystals. The electrostatic interaction between the negatively charged magnetite nanoparticles and the positively charged LDH nanocrystals is sufficient to induce the formation of stable self-assembly of the two components. At a mass ratio of 1 : 0.3 (LDH:Fe 3 O 4 ), all Fe 3 O 4 nanoparticles are attached on the LDH nanocrystals. The resulting nanohybrids maintained an overall positive zeta potential of +42 mV and can form a stable colloidal suspension in water. Separation/re-dispersion of the nanohybrids in the aqueous phase can be easily achieved in the presence/absence of an external magnetic field. The combination of these unique properties allows the nanohybrids to exhibit superior performance in the treatment of organic dyes in wastewater. The colloidal suspension of the nanohybrids leads to fast adsorption kinetics and high adsorption capacity of the acid organic dyes via quick surface adsorption. In addition, the spent nanohybrids can be easily recycled after catalytic regeneration by advanced oxidation technology.

Template‐free Formation of Uniform Urchin‐like α‐FeOOH Hollow Spheres with Superior Capability for Water Treatment

“…[4,6,9,14] Researchers worldwide have used iron oxide nanomaterials to remove toxic heavy metal ions and organic pollutants from waste water, in view of their low cost, natural abundance, and environment-friendly properties. [7,[15][16][17][18][19][20][21][22] In recent years, it has been demonstrated that three-dimensional (3D) hierarchically nanostructured materials exhibit enhanced properties compared to their bulk counterparts. As a result, continuous efforts are being made on the preparation of complex 3D iron oxide nanostructures assembled from low-dimensional building blocks.…”

Adsorption of [AuCl₄]^– on Ultrasonically and Mechanical-Stirring Assisted Mg/Al-NO₃ Hydrotalcite-Magnetite

“…The magnetite (Fe 3 O 4 ) can be modified with inorganic compounds to obtain magnetic adsorbents. Accordingly, the combination of magnetic compound and HT has been developed recently to enhance separation and re-dispersion performance of HT in aqueous solution [13][14].…”

Application of Zno-Fe3O4nano Composite on the Phosphate Removal from Aqueous Solutions: Optimization and Statistical Modeling

“…Many kinds of materials have the potential to remove phosphorus from water, and many materials including waste products have attracted widespread interest due to their potential ability for phosphorus remove, including nZVI 8 ,Clayey peat 9 , Laterite and Red earth 6 Clinoptilolite 10 ,ACFNano HFO 11 ,) ZrO 2 12 sands 13 , fly ash 14 , slag 14 , iron oxide tailings 15 , Ca-based sorbents 16 , alunite 17 , RM, RM700, RMAH 16 , Ca-dolomite, Raw-dolomite 16 and iron-based compounds 7 .Among various nano sized materials, ZnO and Fe 3 O 4 have much attention because ZnO nanoparticles exhibit an efficient photo catalytic removal efficiency through adsorption and decomposition of organic contaminants 18 .Today Most of the studies about phosphate adsorbents have focused on the on the nanoparticles due to the importance of selecting substrates with the highest P adsorption capacity to maximize phosphorus removal. In addition, super paramagnetic Fe 3 O 4 nanoparticles possess a promising adsorption capacity for contaminants along with optimal magnetic properties, showing rapid separation of the adsorbent from solution via a magnetic field 19,20 .…”

“…One of the most important benefits of RSM is the reduction of the number of tests and experiments 21 In recent year optimization of adsorption, biosorption and oxidation processes for different wastewater and synthetic wastewater using RSM have been studied, but only few researchers report about optimization of phosphate removal by nanoparticles using RSM. The most of reports have been focused on Kinetics and equilibrium studies 19,20 .…”