Formation of mixed-ligand zinc(ii) complex-montmorillonite hybrids by solid–solid reactions

Khaorapapong, Nithima; Pimchan, Patcharaporn; Ogawa, Makoto

doi:10.1039/c0dt01736a

Cited by 22 publications

(26 citation statements)

References 43 publications

(55 reference statements)

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“…This species diminished its intensity when Cu(II) ions were added to the suspension at same time that a peak at k = 252 nm appeared and intensified; this absorption signal was ascribed to a binary complex formation. Complex formation between [SWy-1:8-HQ] adsorbed molecules [38,42,[45][46][47][48] and Cu(II) ions occurs in accordance with the reaction:…”

Section: Thermal Characterization and X-ray Diffraction Of Compositesmentioning

confidence: 85%

Thermal and electrochemical studies of Cu(II) 8-hydroxyquinoline organophilic montmorillonite

Lupi

Franzin

Pereira

et al. 2017

J Therm Anal Calorim

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The thermal and electrochemical behavior of montmorillonite clay-8-hydroxyquinoline (8-HQ) film was studied in the absence and presence of aqueous Cu(II) ions. The suggested formation of the ternary complex type: {Pt/ [[ Si-O] n [Cu(II)(OH 2) n (8-HQ) k ]} 3-n-k , with thermal stability up to 350°C, was studied, based on UV-spectroscopy, thermal (DTG-DSC, molecular fluorescence and XRD. The Pt/binary composite film (SWy-1:8-HQ) interphase composed of montmorillonite (SWy-1) with 8-hydroxyquinoline (8-HQ) was investigated by electrochemical techniques analyzing the cyclic voltammograms (CVs) obtained at different scan rates (v) and copper(II) ion concentrations. The mechanical stability of the thin films was demonstrated by performing 80 successive voltammetric cycles. Two pairs of redox peaks, indicated by peaks A/D and C/B were observed. For Cu(II) ions in solution, the log i p 9 log v relationships showed processes controlled by adsorption, peaks A/D, and by diffusion, peaks C/B. The analysis of i p / v 1/2 and i pa /i pc versus v suggested two homogeneous coupled reactions, being both reversible and fast kinetic chemical reactions, associated to the mechanisms chemical-electrochemical (CE) and electrochemical-chemical (EC), respectively. The modified electrode showed a good sensitivity to low concentrations of Cu(II) ions, which opens the possibility of being used in chemical analysis. Keywords Organic montmorillonite composites Á TG-DTA simultaneous, Cu(II) ions Á Reversible coupled reactions Á Cu(I)/Cu(II) redox species Electronic supplementary material The online version of this article (

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Section: Thermal Characterization and X-ray Diffraction Of Compositesmentioning

confidence: 85%

Thermal and electrochemical studies of Cu(II) 8-hydroxyquinoline organophilic montmorillonite

Lupi

Franzin

Pereira

et al. 2017

J Therm Anal Calorim

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“…Figure 3 II shows spectra of a freshly resuspended SWy-1:8-HQ binary composite. This UV spectra shows a peak at k = 239 nm (peak a) attributed to a hydrophobic dimeric species, (8-HQ) 2 , which is of a maximum intensity, and a peak of lower intensity near k = 252 nm attributed to a monomeric species, 8-HQ adsorbed into the clay [27], according to the equation: According to Fig. 3I, the increase in C Fe(III) ions causes the appearance of new absorption peaks in the UV range of (250 B k B 280) nm positioned at k = 258 and 272 nm, suggesting the formation of a new species in accordance with the TG-DTA data, which was attributed to the ternary composite, SWy-1:8-HQ-Fe(III).…”

Section: Clay Binary Film Investigationmentioning

confidence: 99%

“…3 revealed three absorption peaks: Ia, Ib, and Ic in the range of (225 B k B 300) nm. The peak Ia (k = 239 nm) refers to the dimeric species (8-HQ) 2 as described above [26][27][28].…”

Section: Clay Binary Film Investigationmentioning

confidence: 99%

“…These characteristics combined with the high surface area and swelling capacity of smectite clays, used in the present work, encourage significant investment in research in order to enhance the applications conferred to these materials. The use of an expansive 2:1 montmorillonite clay (smectite class) in association with organic molecules, such as 8-hydroxyquinoline (8-HQ) [26][27][28], increases the stability of the new composite and improves its adsorption capacity of inorganic ions (M n? ) [29,30].…”

Section: Introductionmentioning

confidence: 99%

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Thermal and electrochemical studies of Fe(III) organophilic montmorillonite

Franzin¹,

Lupi²,

Martins³

et al. 2017

J Therm Anal Calorim

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This study aimed at investigating the thermal and electrochemical behavior of montmorillonite clay-8hydroxyquinoline (8-HQ) film in the absence and presence of aqueous Fe(III) ions. The solid film characterization by means of UV spectroscopy, thermal (TG/DTG and TG-DTA, simultaneous) studies, SEM and optical images, and XRD suggested the formation of the ternary complex type: {Pt/[[Si-O] n [Fe(III)(OH 2) 3 (8-HQ) k ]} 3-n-k , with thermal stability up to 300°C. The electrochemical study was carried out on a platinum electrode modified by mechanical deposition of a thin solid film of the binary composite (SWy-1:8-HQ) from an aqueous suspension. The mechanical stability of the film was followed by performing 80 cyclic voltammograms. The electrochemical behavior of the modified electrode was investigated using cyclic voltammetry (CV) at different ferric ions concentration (C Fe(III)), followed by a study of the effect of the scan rate (v) with a fixed C Fe(III) ions. In the CVs, two independent pairs of current peaks, A/D and C/B, were observed. For Fe(III) ions in solution, log i p versus log v relationship shows a process controlled first by adsorption (pair of peaks A/D) and then by diffusion control (pair of peaks C/B). The current function i p /v 1/2 versus v and i p a /i p c versus v allowed a suggestion of two homogeneous coupled chemical reactions associated with CE and EC mechanisms, respectively, both with fast reversible chemical reactions. The first investigation of a modified electrode showed good sensitivity (S = 25.1 lA/lmol L-1) to low concentrations of ferric ions and detection limit [LOD = (2.4 ± 0.01) lmol L-1 ] and high sensitivity to traces of O 2 , showing that this system has great analytical potentials.

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“…Smectite group of clay minerals is an important class of layered materials, which has such peculiar characteristics as swelling behavior, large surface area, adsorptive property, and ion exchange property for immobilizing organic guest molecules (van Olphen, 1977). Numerous works have been done on the hybrids of organic and inorganic substances with pristine and organically modified smectites to show the modified properties of the immobilized species confined in the interlayer space of the clay minerals (Khaorapapong et al, 20022011a, 2011bLagaly, et al, 2006;Khaorapapong and Ogawa, 2007, 2010, 2011Khaorapapong, 2010;Ontam et al, 2011;Pimchan et al, 2011Pimchan et al, , 2014aPimchan et al, , 2014bOkada et al, 2014). The preparation of smectite-based hybrids is worth investigating because the spatial distribution smectites and the orientation of guests may affect the physicochemical characteristics .…”

Section: Introductionmentioning

confidence: 99%