Chemical, structural and hyperfine characterization of goethites with simultaneous incorporation of manganese, cobalt and aluminum ions

Álvarez, Mariana; Tufo, Ana Elisabeth; Zenobi, C.; Ramos, Cinthia Paula; Sileo, Elsa E.

doi:10.1016/j.chemgeo.2015.08.022

Cited by 26 publications

(15 citation statements)

References 31 publications

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“…The Al‐substituted goethite (Co 0 Al 8.5 ) showed the lowest SSA (26 ± 1 m 2 g −1 ). The tri‐substituted oxy(hydr)oxide showed high SSA, related to the strong influence of Co incorporation (64 ± 1 m 2 g −1 ) .…”

Section: Resultsmentioning

confidence: 99%

“…Two series of Me‐goethites, (MnCo)‐goethites and (CoAl)‐goethites, were prepared as described elsewhere . The target metal content χ Me was kept constant at 12%:

X_{M e} = m o l M e \times 100 / (normalm normalo normall normalM normale + normalm normalo normall normalF normale)

in order to avoid the formation of other phases except goethite.…”

Section: Methodsmentioning

confidence: 99%

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Multi‐Metal‐Substituted‐Goethite as an Effective Catalyst for Azo Dye Wastewater Oxidation

Schlichter

Diez

Zenobi

et al. 2016

CLEAN Soil Air Water

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Research ArticleMulti-Metal-Substituted-Goethite as an Effective Catalyst for Azo Dye Wastewater Oxidation Different samples of goethite modified with cobalt, manganese, or aluminum were synthesized and characterized by means of X-ray diffraction, chemical analysis, scanning electron microscopy, zeta potential measurements, and N 2 adsorptiondesorption isotherm analysis. The goethite oxides were tested as efficient catalysts for the degradation of methyl orange (MO, sodium 4-[(4-dimethylamino)phenylazo] benzenesulfonate), a sulfonated azo dye indicator, employing potassium persulfate (PS) in water, at pH 3. The Mn, Co, and Al substitution in goethite gave rise to active sites for PS activation. The most effective catalyst reached 93% of degradation at 120 min of reaction. The increase of temperature led to an expected conversion enhancement, and kinetic parameters were calculated for one of the evaluated catalysts. MO degradation curves best fitted to pseudo-second order kinetics. The extent of mineralization, measured as total removed organic carbon (TOC), was also monitored. A significant degree of mineralization was achieved and confirmed by TOC analysis. A mechanism for MO oxidation with SO •À 4 radicals was discarded and a pathway involving peroxymonosulfate species was proposed. The results indicate that the goethitesubstituted oxides are effective catalysts for the studied azo dye degradation in aqueous solution.

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Section: Resultsmentioning

confidence: 99%

“…Two series of Me‐goethites, (MnCo)‐goethites and (CoAl)‐goethites, were prepared as described elsewhere . The target metal content χ Me was kept constant at 12%:

X_{M e} = m o l M e \times 100 / (normalm normalo normall normalM normale + normalm normalo normall normalF normale)

in order to avoid the formation of other phases except goethite.…”

Section: Methodsmentioning

confidence: 99%

Multi‐Metal‐Substituted‐Goethite as an Effective Catalyst for Azo Dye Wastewater Oxidation

Schlichter

Diez

Zenobi

et al. 2016

CLEAN Soil Air Water

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“…The overall charge of goethite and hematite may be affected by the presence of foreign metal ions, and when a partial substitution of Fe(III) by other ion occurs, a change in the value of the zpc with respect to pure iron oxide can be expected. Alvarez's work showed that the substitution of Mn in goethite has lowered the zpc value to 5.8, compared to the pure goethite sample with zpc=7.3 (Alvarez et al, 2015).…”

Section: Zeta Potentialmentioning

confidence: 99%

“…Naturally existing goethite and hematite are usually not pure, and are associated with a number of cations that are isovalent or heterovalent to Fe(III) (Alvarez, Tufo, Zenobi, Ramos, & Sileo, 2015). Trace metal, cobalt(II), nickel(II), and manganese(II) substitution are the most common phenomenon for goethite and hematite minerals (Rout, Dash, Mohapatra, & Anand, 2014).…”

Section: Chapter I Introductionmentioning

confidence: 99%

“…Organic ligands common in water are formate, acetate, citrate and oxalate (Graedel, Mandich, & Weschler, 1986;Zuo & Hoigne, 1992), and among them, oxalate was the most effective ligand (Panias, Taxiarchou, Douni, Paspaliaris, & Kontopoulos, 1996), and it could affect iron dissolution kinetics significantly. Mobility of iron in aquatic environments can be enhanced by (1) proton-promoted dissolution that leads metal-oxygen bonds to be loosened, thus lead to iron release (Xu & Gao, 2008), (2) ligand-promoted dissolution that forms soluble Fe(III) complexes with ligands (Wang, Schenkeveld, Kraemer, & Giammar, 2015) and (3) reduction of Fe(III) to the more soluble form of Fe (II) under anoxic environment or with the presence of reductive solution (Dos Santos Afonso, Morando, Blesa, Banwart, & Stumm, 1990) It has been reported that trace metal dopant could affect iron oxide structure and properties markedly including surface specific area, particle size (Mohapatra, Anand, Das, Upadhyay, & Verma, 2002;Warner et al, 2012), crystallization (H. Ebinger & G. Schulze, 1989), zeta potential (Alvarez et al, 2015) and adsorption behavior towards phosphate (Li et al, 2016) and metal ions (Rout et al, 2014). The change and transformation of oxide structure could affect its dissolution property significantly (Latta, A Gorski, & Scherer, 2012), and the mineral's surface structure could predict the dissolution kinetics.…”

Section: Chapter I Introductionmentioning

confidence: 99%

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Effects of cobalt, nickel, and manganese doping on the structure and dissolution properties of goethite and hematite

Cui¹

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Trace metal dopant in goethite and hematite are common in soils, groundwater and sediments, and have strong influence on the structure and physicochemical properties of goethite and hematite. In this work, a series of Co, Ni and Mn-doped goethites and hematites were synthesized, fully characterized by powder X-ray diffraction (XRD), and the zeta potential of samples have been measured to study their structure. The dissolution kinetics of pure and trace metal doped goethites and hematites in proton-promoted, ligandpromoted, reductive ligand-promoted solutions were also investigated. Characterization results demonstrated that trace metal dopants affect crystal unit cell parameters, increase cell volume, and decreased the relative proportion of the main crystal facet. Additionally, zeta potential measurement indicated that trace metal dopants lower the zero point of charge of oxide. The dissolution experiments showed that trace metal dopant affect metal release extent and rate coefficient of goethite and hematite. Additionally, the dissolution experiments also indicated that the presence of ligand would promote metal release from goethite and hematite. A synergistic effect of reductant and ligand on the rate and extent of goethite and hematite dissolution was possible from the observation but still need more work to identify. The results of this research facilitate better understanding of the Co, Ni and Mn substitution on the structure and properties of goethite and hematite, and their dissolution process in different aquatic systems.

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Removal of Cr(VI) from Wastewater by a Novel Adsorbent of Magnetic Goethite: Adsorption Performance and Adsorbent Characterisation

Liu

Chen

et al. 2019

ChemistrySelect

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A novel adsorbent of magnetic goethite was prepared by neutralisation hydrolysis and employed for Cr(VI) adsorption from aqueous solution. The magnetic goethite adsorbent was characterised by using scanning electron microscopy (SEM), X‐ray diffractometer (XRD), vibrating sample magnetometer (VSM), fourier transform infrared (FTIR), brunauer‐Emmett‐Teller (BET) and X‐ray photoelectron spectroscopy (XPS) method. VSM showed that the prepared adsorbents are super‐paramagnetic iron hydroxide. FTIR spectra revealed that magnetic goethite have ‐OH and other functional groups. The effects of various factors, including pH, adsorbent dosage, initial concentration, and ion concentration, were evaluated. Under the conditions of pH 3, 4 g/L magnetic goethite, 20 mg/L Cr(VI) concentration, and 0.01 mol/L NaNO3, the removal efficiency of Cr (VI) reached 88.2% and the adsorption capacity of the adsorbent reached 4.32 mg/g. The adsorption kinetic tests showed that the adsorption of Cr(VI) on the adsorbent matched well with pseudo‐second‐order kinetics, indicating the occurrence of chemisorption. The fitting of the Langmuir isotherm model showed that the adsorption of Cr(VI) on magnetic goethite was monolayer adsorption. On the other hand, thermodynamic studies conjectured that the adsorption processes of magnetic goethite for Cr(VI) was endothermic and spontaneous. These results suggest that magnetic goethite has great potential for the removal of heavy metals from wastewater.

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Chemical, structural and hyperfine characterization of goethites with simultaneous incorporation of manganese, cobalt and aluminum ions

Cited by 26 publications

References 31 publications

Multi‐Metal‐Substituted‐Goethite as an Effective Catalyst for Azo Dye Wastewater Oxidation

Multi‐Metal‐Substituted‐Goethite as an Effective Catalyst for Azo Dye Wastewater Oxidation

Effects of cobalt, nickel, and manganese doping on the structure and dissolution properties of goethite and hematite

Removal of Cr(VI) from Wastewater by a Novel Adsorbent of Magnetic Goethite: Adsorption Performance and Adsorbent Characterisation

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