Solvothermal Ion Exchange of Aliphatic Dicarboxylates into the Gallery Space of Layered Double Hydroxides Immobilized on Si Substrates

The selectivity towards halides and the mechanism of ion exchange of ZnAl-LDH in the chloride form (X− = F−, Br−, I−) were investigated using ion exchange isotherms of Cl−/X−.

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Studies on selective adsorbents for oxo-anions. Nitrate ion-exchange properties of layered double hydroxides with different metal atoms

Green Chemistry ◽

10.1039/b314938m ◽

2004 ◽

Vol 6 (2) ◽

pp. 104 ◽

Cited By ~ 58

Author(s):

Satoko Tezuka ◽

Ramesh Chitrakar ◽

Akinari Sonoda ◽

Kenta Ooi ◽

Tahei Tomida

Keyword(s):

Ion Exchange ◽

Layered Double Hydroxides ◽

Nitrate Ion ◽

Metal Atoms ◽

Oxo Anions ◽

Double Hydroxides ◽

Exchange Properties

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Pathways of phosphate uptake from aqueous solution by ZnAl layered double hydroxides

Water Science & Technology ◽

10.2166/wst.2013.049 ◽

2013 ◽

Vol 67 (8) ◽

pp. 1757-1763 ◽

Cited By ~ 8

Author(s):

X. Cheng ◽

Y. Wang ◽

Z. Sun ◽

D. Sun ◽

A. Wang

Keyword(s):

Ion Exchange ◽

Layered Double Hydroxides ◽

Surface Adsorption ◽

Chloride Ion ◽

Bulk Solution ◽

Entire Study ◽

Pseudo Second Order ◽

Interlayer Anion ◽

Acidic Conditions ◽

Double Hydroxides

ZnAl layered double hydroxides (LDHs) were prepared by urea hydrolysis-based coprecipitation for removing phosphate from aqueous solutions. The chemical formula of the product was determined as Zn5.54Al3.02(OH)8.73(CO3)0.57Cl5.66·7.84H2O. Chloride ion was the major interlayer anion of the ZnAl LDHs. Adsorption of phosphate onto the ZnAl sorbent over the entire study period was not in close agreement with pseudo-first-order or pseudo-second-order models. The adsorption can be divided into two steps. A fast adsorption was observed during the first 10 h with a marked increase in the concentration of Cl− in the bulk solution. This indicated that the adsorption of phosphate was largely attributed to the ion exchange between phosphate and the interlayer Cl−. A second fast adsorption of phosphate occurred after 10 h. During this period, the pH increased slowly, whereas the Cl− concentration was stable. The uptake of phosphate was likely attributed to OH−–H2PO4−/HPO42− ion exchange as well as surface adsorption/complexation. Acidic conditions favored adsorption of phosphate by ZnAl LDHs, which is consistent with the pH increases during the adsorption. Coexisting anions, e.g., SO42− and CO32−, are competitive ions for the adsorption of phosphate. The results verify the contribution of ion exchange and surface adsorption/complexation in the removal of phosphate by ZnAl LDHs.

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Density Functional Theory Investigating Interlayer Structure and Ion-Exchange Properties of Mg/Al Layered Double Hydroxides

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.2293 ◽

2011 ◽

Vol 239-242 ◽

pp. 2293-2296 ◽

Cited By ~ 1

Author(s):

Guo Xiang Pan ◽

Feng Cao ◽

Jin Tian Yang ◽

Zhe Ming Ni ◽

Pei Song Tang ◽

...

Keyword(s):

Density Functional Theory ◽

Ion Exchange ◽

Layered Double Hydroxides ◽

Density Functional ◽

Interlayer Spacing ◽

Mulliken Charge ◽

Functional Theory ◽

Host Layer ◽

Interlayer Structure ◽

Double Hydroxides

The two-sheets model was proposed to investigate interlayer structure and properties of Mg/Al layered double hydroxides (LDHs) containing F-, Cl-, Br-, I- and OH- using density functional theory (DFT). The results show that four types of halogen anions in the interlayer of LDHs have the same configurations due to simple sphere structures of isolated anions. As the size of halide anions increasing, the interlayer spacing dc increase. Mulliken charge analysis illustrates that the host layers interact with the guest anions by the electrostatic interaction and hydrogen bonding, and the charge transfers from anions to layers. The frontier orbital of the host layer interacts with that of the guest anions, and the electron transfers from HOMO of anions to LUMO of the host layer. Moreover, the order in the absolute value of binding energy is: OH- >F- >Cl- >Br- >I-, that remains consistent with ion-exchange ability of LDHs reported.

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