IR and laser raman studies on peroxo fluoro species of zirconium

Jere, G.V.; Santhamma, M. T.

doi:10.1016/s0020-1693(00)93851-9

Cited by 32 publications

(16 citation statements)

References 11 publications

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“…The broad peaks centered at 992 and 1506 cm –1 were assigned to Zr–O and Zr–OH bonds, respectively, while peaks around 880 and 1108 cm –1 were related to C–O–C and −OH bonds from the OA and Zr-oxalate complex, respectively. Bands at 1308 and 1348 cm –1 denoted a combination of Zr–O and Zr–OH vibration bonds. , The peak at 3400 cm –1 was due to the stretching and bending modes of coordinated water and the −OH bond from Zr–OH and the organic acid. A narrow band of big intensity at 1680 cm –1 indicated the presence of CO groups.…”

Section: Results and Discussionmentioning

confidence: 99%

Zirconium–Carbon Hybrid Sorbent for Removal of Fluoride from Water: Oxalic Acid Mediated Zr(IV) Assembly and Adsorption Mechanism

Velázquez-Jiménez

Hurt

Matos

et al. 2013

Environ. Sci. Technol.

193

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When activated carbon (AC) is modified with zirconium(IV) by impregnation or precipitation, the fluoride adsorption capacity is typically improved. There is significant potential to improve these hybrid sorbent by controlling the impregnation conditions, which determine the assembly and dispersion of the Zr phases on carbon surfaces. Here, commercial activated carbon was modified with Zr(IV) together with oxalic acid (OA) used to maximize the zirconium dispersion and enhance fluoride adsorption. Adsorption experiments were carried out at pH 7 and 25 °C with a fluoride concentration of 40 mg L−1. The OA/Zr ratio was varied to determine the optimal conditions for subsequent fluoride adsorption. The data was analyzed using the Langmuir and Freundlich isotherm models. FTIR, XPS and the surface charge distribution were performed to elucidate the adsorption mechanism. Potentiometric titrations showed that the modified activated carbon (ZrOx-AC) possesses positive charge at pH lower than 7, and FTIR analysis demonstrated that zirconium ions interact mainly with carboxylic groups on the activated carbon surfaces. Moreover, XPS analysis demonstrated that Zr(IV) interacts with oxalate ions, and the fluoride adsorption mechanism is likely to involve –OH− exchange from zirconyl oxalate complexes.

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Section: Results and Discussionmentioning

confidence: 99%

Zirconium–Carbon Hybrid Sorbent for Removal of Fluoride from Water: Oxalic Acid Mediated Zr(IV) Assembly and Adsorption Mechanism

Velázquez-Jiménez

Hurt

Matos

et al. 2013

Environ. Sci. Technol.

193

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“…Asymmetric flexural vibrations ν as (Zr–F) were attributed to a series of peaks located at 488–418 cm −1 and vibrations of type n(Zr–F) at 390–402 cm −1 . Finally, a series of peaks located at a range of 246–356 cm −1 were assigned to the symmetric, asymmetric, and bending vibrations of the F–Zr–F type [ 58 ]. Based on these results, the Zr–F interaction after adsorption of fluoride ions can be confirmed.…”

Section: Resultsmentioning

confidence: 99%

Amino Acid Complexes of Zirconium in a Carbon Composite for the Efficient Removal of Fluoride Ions from Water

González-Aguiñaga

Pérez-Tavares

Patakfalvi

et al. 2022

IJERPH

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Amino acid complexes of zirconia represent an entirely new class of materials that were synthesized and studied for the first time for the decontamination of fluoride ion containing aqueous solutions. Glutamic and aspartic acid complexes of zirconia assembled with thin carbon (stacked graphene oxide) platelets deriving from graphite oxide (GO) were synthesized by a two-step method to prepare adsorbents. The characterization of the complexes was carried out using infrared spectroscopy to determine the functional groups and the types of interaction between the composites and fluoride ions. To reveal the mechanisms and extent of adsorption, two types of batch adsorption measurements were performed: (i) varying equilibrium fluoride ion concentrations to construct adsorption isotherms at pH = 7 in the absence of added electrolytes and (ii) using fixed initial fluoride ion concentrations (10 mg/L) with a variation of either the pH or the concentration of a series of salts that potentially interfere with adsorption. The experimental adsorption isotherms were fitted by three different theoretical isotherm equations, and they are described most appropriately by the two-site Langmuir model for both adsorbents. The adsorption capacities of Zr-glutamic acid-graphite oxide and Zr-aspartic acid-graphite oxide are 105.3 and 101.0 mg/g, respectively. We found that two distinct binding modes are combined in the Zr-amino acid complexes: at low solution concentrations, F− ions are preferentially adsorbed by coordinating to the surface Zr species up to a capacity of ca. 10 mg/g. At higher concentrations, however, large amounts of fluoride ions may undergo anion exchange processes and physisorption may occur on the positively charged ammonium moieties of the interfacially bound amino acid molecules. The high adsorption capacity and affinity of the studied dicarboxylate-type amino acids demonstrate that amino acid complexes of zirconia are highly variable materials for the safe and efficient capture of strong Lewis base-type ions such as fluoride.

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“…This peak is absent in the spectrum of the diatom and present only in the spectrum of the composite supporting the presence of ZrO 2 particles only in the composite. Moreover, both the spectra showed peaks at 1108 cm −1 and between 3300 and 3500 cm −1 which were attributed to symmetrical stretch of ν si-O-si and ν si–OH respectively [39].…”

Section: Resultsmentioning

confidence: 99%

Nanostructured Diatom-ZrO2 composite as a selective and highly sensitive enzyme free electrochemical sensor for detection of methyl parathion

Gannavarapu

Ganesh

Thakkar

et al. 2019

Sensors and Actuators B: Chemical

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In the current work we report a simple and scalable technique for synthesis of ordered nanoporous Si-ZrO2 composite derived from the diatom Phaeodactylum tricornutum. The composite was well characterized using SEM, TEM-EDX, FTIR, TGA, BET and DLS. The diatom-ZrO2 was found to have a specific surface area of 140 m2/g, Si:Zr ratio of 1:4 and a particle size of 80 ± 2 nm. This composite was evaluated as an enzyme free electrochemical sensor towards the detection of methyl parathion (MP) and showed excellent sensing ability at extremely low detection limits of 54.3 pM and a linear concentration range of 3.4 nM to 64 μM. The diatom-ZrO2 composite was also found to be highly selective towards MP as shown by its response even in the presence of high concentrations of other interfering molecules and ions.

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IR and laser raman studies on peroxo fluoro species of zirconium

Cited by 32 publications

References 11 publications

Zirconium–Carbon Hybrid Sorbent for Removal of Fluoride from Water: Oxalic Acid Mediated Zr(IV) Assembly and Adsorption Mechanism

Zirconium–Carbon Hybrid Sorbent for Removal of Fluoride from Water: Oxalic Acid Mediated Zr(IV) Assembly and Adsorption Mechanism

Amino Acid Complexes of Zirconium in a Carbon Composite for the Efficient Removal of Fluoride Ions from Water

Nanostructured Diatom-ZrO2 composite as a selective and highly sensitive enzyme free electrochemical sensor for detection of methyl parathion

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