Iron oxyhydroxide nanostructured in montmorillonite clays: Preparation and characterization

Villalba, Juan Carlo; Constantino, Vera Regina Leopoldo; Anaissi, Fauze Jacó

doi:10.1016/j.jcis.2010.04.057

Cited by 33 publications

(10 citation statements)

References 19 publications

(25 reference statements)

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“…For example, diffuse reflectance Fourier‐transformed infrared spectroscopic investigation shows that the surface of γ ‐Al 2 O 3 was transformed into a bayerite polymorph upon ageing in solution (Arai et al , 2001). Thus, the abundant hydroxyl groups on Al oxide surfaces create a layer of coating on silicates with hydrogen and coordination bonds (Goldberg, 1989; Beauvais & Bertaux, 2002; Orolínová & Mockovčiaková, 2009; Villalba et al , 2010). McAtee & Wells (1967) verified with electron microscopy that, when kaolinite was mixed with gibbsite, the clay particles were coated by Al oxides.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, the sesquioxide coating also evidently changes the electrochemical properties of phyllosilicates in acidic variable‐charge soils. Coating occurs through the formation of chemical bonds, such as hydrogen bonds and coordination bonds, between the sesquioxides and phyllosilicates (Beauvais & Bertaux, 2002; Orolínová & Mockovčiaková, 2009; Villalba et al , 2010). Once formed, these coatings are stable in moderately changing environments, such as a change in pH or ionic strength in variable‐charge soils (Goldberg, 1989).…”

Section: Introductionmentioning

confidence: 99%

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Inhibition of acidification of kaolinite and an Alfisol by aluminum oxides through electrical double‐layer interaction and coating

2013

European J Soil Science

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Soil chemical properties are affected significantly by surface charge characteristics of the soil. Interaction between oppositely charged particles in variable‐charge soils plays an important role in variation of soil electrochemical properties. In this study, the effects of Al oxides on surface charge and acidity properties of kaolinite and an Alfisol during electrodialysis were investigated. The results indicated that Al oxides, when mixed into kaolinite or the Alfisol, decreased the effective cation exchange capacity (ECEC) and exchangeable acidity and inhibited the decrease in pH. Gibbsite had less effect than γ‐Al2O3 and amorphous Al(OH)3 in reducing the ECEC and acidity of kaolinite and the Alfisol; γ‐Al2O3 and amorphous Al(OH)3 displayed comparable effects. However, this effect is inconsistent with the order of the surface positive charge per unit mass that the Al oxides carried. Their effect on the ECEC of kaolinite and Alfisol varied irreversibly with ionic strength of the bathing solutions. X‐ray diffraction spectra indicated that amorphous Al(OH)3 and γ‐Al2O3 were more effective than gibbsite in decreasing peak intensity of electro‐dialyzed kaolinite when mixed with these Al oxides at the same rate. The results demonstrated that Al oxides could decrease the effective negative charge and inhibit acidification of kaolinite and an Alfisol through diffuse‐double‐layer overlapping between oppositely charged particles and coating of Al oxides on these materials. Both mechanisms intensified with increasing rate of added Al oxides, which can therefore act as anti‐acidification agents in variable‐charge soils.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Inhibition of acidification of kaolinite and an Alfisol by aluminum oxides through electrical double‐layer interaction and coating

2013

European J Soil Science

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“…A convenient method to control aggregation and particle size involves the preparation of iron hydroxide particles (e.g. akaganeite) in a template, such as clay, polymer or Fe‐exchanged natural zeolite …”

Section: Introductionmentioning

confidence: 99%

Modification of a natural zeolite with Fe(III) for simultaneous phosphate and ammonium removal from aqueous solutions

Guaya

Valderrama

Farrán

et al. 2015

J of Chemical Tech & Biotech

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BACKGROUND: The incorporation of Fe(III) was performed in a natural clinoptilolite (Z-N) for simultaneous phosphate and ammonium removal. RESULTS: The existence of hydroxyl groups (congruent to Fe-OH) in the iron zeolite (Z-Fe) enhances the phosphate uptake from 0.6 +/- 0.1 mg-P g(-1) in Z-N to 3.4 +/- 0.2 mg-P g(-1) in Z-Fe. However, the ammonium sorption capacity slightly decreases from 33 +/- 2 mg-N g(-1) in Z-N to 27 +/- 2 mg-N g(-1) in Z-Fe. The equilibrium and kinetics sorption were well explained by the Langmuir isotherm and the intraparticle diffusion model, respectively. CONCLUSIONS: Both the phosphate and ammonium uptake were slightly affected by the coexistence of competing ions. The phosphate sorption capacity of iron zeolite was decreased in the regeneration cycles. Desorption using a 1 mol L-1 NaOH solution under dynamic conditions provided higher enrichment factors for ammonium than phosphatePeer ReviewedPostprint (author's final draft

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“…In the infrared spectrum of β-FeOOH samples after the dark-Fenton process and the photo-Fenton process, the absorption peaks at wavelength 1628, 1392, 1132 and 1060 cm −1 were attributed to the O-H vibrations of absorbed H 2 O molecules or structural OH groups [15,17]. The other absorption peaks at wavelength 844, 696 and 634 cm −1 were assigned to the Fe-O vibration modes in β-FeOOH [15,18,19]. No characteristic absorption peaks ascribed to the MO were observed in the both dark-Fenton process and photoFenton process, which implied that the MO degradation rate on the β-FeOOH surface was quite fast.…”

Section: Photodegradation Of Mo By β-Feooh/h 2 O 2 With or Without Uvmentioning

confidence: 99%

Template-Free Hydrothermal Synthesis of β-FeOOH Nanorods and Their Catalytic Activity in the Degradation of Methyl Orange by a Photo-Fenton-Like Process

Xu¹,

Liang²,

Zhou³

2013

OJINM

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The rod-shaped form of crystalline β-FeOOH (akaganeite) was prepared by the template-free hydrothermal method with urea as the homogeneous precipitant. X-ray diffraction, field-emission scanning electron microscope and Fourier transform infrared spectrum were used to characterize the resulting products. The degradation of methyl orange (MO) was studied using the prepared nanostructure materials in a photo-Fenton-like process. MO degradation was effectively achieved by hydroxyl radicals that were generated in the heterogeneous catalysis process. Specific surface area of the prepared β-FeOOH was an important factor affecting the efficiency of MO degradation, which depended on the synthesis conditions such as the reaction temperature, the initial concentration of urea and FeCl 3 ·6H 2 O as well as the n(urea)/n(Fe 3+ ) ratio. The photodegradation efficiencies slightly decreased with the increase of initial pH in the range of 4.5 -9.5, which indicated the prepared β-FeOOH catalyst can well overcome the drawback of a narrow pH range of homogeneous Fenton reaction. β-FeOOH catalysts loading and H 2 O 2 concentration also play important effect on the degradation efficiency of MO. The prepared β-FeOOH showed good ability of reuse for multiple trials.

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Iron oxyhydroxide nanostructured in montmorillonite clays: Preparation and characterization

Cited by 33 publications

References 19 publications

Inhibition of acidification of kaolinite and an Alfisol by aluminum oxides through electrical double‐layer interaction and coating

Inhibition of acidification of kaolinite and an Alfisol by aluminum oxides through electrical double‐layer interaction and coating

Modification of a natural zeolite with Fe(III) for simultaneous phosphate and ammonium removal from aqueous solutions

Template-Free Hydrothermal Synthesis of β-FeOOH Nanorods and Their Catalytic Activity in the Degradation of Methyl Orange by a Photo-Fenton-Like Process

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