Nitrogen-rich core/shell magnetic nanostructures for selective adsorption and separation of anionic dyes from aqueous solution

Abstract

Novel core/shell nanostructured Fe3O4@NH2@PEI composites were successfully prepared and used to selectively adsorb and separate anionic dyes from a complex system.

Facile crosslinking synthesis of hyperbranch-substrate nanonetwork magnetite nanocomposite for the fast and highly efficient removal of lead ions and anionic dyes from aqueous solutions

“…Besides, considerable adsorption capacity can be attributed to other chemical interactions and physics forces such as hydrogen bonding for dyes 18 and complexation for metal ions 76 , which make the adsorbates immobilized. Specifically, the adsorption equilibrium was reached within 20 min by Pb 2+ and 10 min for MO, respectively.…”

Simultaneous capture of methyl orange and chromium(vi) from complex wastewater using polyethylenimine cation decorated magnetic carbon nanotubes as a recyclable adsorbent

“…44 The strong peak at around 587 cm À1 in both MWCNTs@Fe 3 O 4 and MWCNTs@Fe 3 O 4 /PEI was attributed to the stretching mode of Fe-O bonds in the Fe 3 O 4 nanoparticles. 45 Owing to the introduction of the PEI molecules, some newly appeared peaks were observed in the FT-IR spectrum of MWCNTs@Fe 3 O 4 /PEI. The absorption band at 3416 cm À1 , overlapped with the -OH of the MWCNTs and was much stronger than that of the MWCNTs@Fe 3 O 4 , from the stretch vibration of N-H bond in PEI.…”

“…The two peaks at 2927 and 2847 cm À1 are due to the symmetric and asymmetric stretches of the -CH 2 groups in PEI, respectively. 45 TGA curves of the samples were depicted in Fig. 2c.…”

“…Initial solution pH is one of the most important factors inuencing the adsorption behaviour of ionizable compounds, because the solution pH not only affects the ionization state of the adsorbates but also determines the surface charge of adsorbents. 45 Thus, the effects of solution pH varying from 2 to 11 on the uptake capacities of three different adsorbents for anionic MO and Cr(VI) were investigated in the present work. It is obvious from Fig.…”

Magnetic biochar from alkali-activated rice straw for removal of rhodamine B from aqueous solution

“…4(b), the adsorption of RhB onto the adsorbent was slightly enhanced in the presence of Na + , Ca 2+ and Cl − . In general, the adsorption processes at the solid/liquid interface could be affected by the increased ionic strength as a result of the salting out and the squeezing out effects [41,42]. The salting out effect was previously found to promote the adsorption of 17β-estradiol onto magnetic biochars at a concentration of NaCl below 0.01 mol L −1 , but it was subsequently neutralized by the squeezing out effect at high NaCl concentration [31].…”