Influence of physical/chemical treatments to delamination of nanohybrid kaolinite-dipicolinate

Silva, Adrieli Cristina da; Ciuffi, Kátia J.; Reis, Márcio José dos; Calefi, Paulo S.; Faria, Emerson H. de

doi:10.1016/j.clay.2016.03.023

Cited by 9 publications

(4 citation statements)

References 32 publications

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“…This last reflection is characteristic of the ab plane; the absence of changes in directions ab suggested that this decrease was related to changes in the stacking of plates along the c-direction, with a lower number of neatly stacked layered structures. [36][37][38][39] These results also demonstrated that the acidic or basic conditions used in the preparation of the samples were not aggressive enough to cause changes in the structure of kaolinite. No peaks due to TiO 2 phases were recorded, although it may be remarked that the characteristic reflections of anatase are very close to those from kaolinite, a fact which made difficult the analysis on these solids.…”

Section: Characterization Of the Solidsmentioning

confidence: 78%

“…This decrease may be caused by the covering of kaolinite surface with titanium alkoxide species, and the attachment of titanium dioxide and CoMPc to the kaolinite layers after hydrolysis and condensation of the alkoxide, interacting with the kaolinite surface. [36][37][38][39] The intensities of reflections (001) and (002) and also the ratio between their intensities-(001)/(020)-decreased for the derived materials (CAR, CBR, CAR-CoMPc and CBR-CoMPc) (Table S2, SI section), suggesting that the treatments could promote changes in the stacking of the kaolinite layers. Other evidence was the decrease in the ratio between the intensities of the reflections (020) and (006).…”

Section: Characterization Of the Solidsmentioning

confidence: 99%

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Kaolinite/TiO2/cobalt(II) Tetracarboxymetallophthalocyanine Nanocomposites as Heterogeneous Photocatalysts for Decomposition of Organic Pollutants Trimethoprim, Caffeine and Prometryn

Silva¹,

Ribeiro²,

Nassar³

et al. 2019

J. Braz. Chem. Soc.

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São Simão's Brazilian kaolinite has been treated with titanium(IV) isopropoxide and cobalt(II) tetracarboxymetallophthalocyanine under different conditions (acidic or basic), leading, after drying at 100 ºC, to new titania-doped cobalt(II)-metallophthalocyanine/kaolinite solids. These solids were characterized by chemical analysis, powder X-ray diffraction, Fourier transform infrared spectroscopy, thermal analyses and nitrogen adsorption. No significant changes were observed by diffractometry, but the specific surface area depended of the synthetic route followed. The ability of these solids for photodegradation of trimethoprim, caffeine and prometryn was evaluated. The photodegradation was followed via mass spectrometry and UV-Vis absorption spectroscopy. The presence of photodegradation by-products was verified in all cases. All the photocatalysts showed high photodegradation rate against prometryn, trimethoprim and caffeine, the degradation efficiencies were 54, 30 and 90%, respectively, when using the heterogeneous photocatalysts. Comparison with commercial TiO 2 (Degusa ®) proved that the synthesized photocatalyst based on kaolinite present higher degradation rate than isolated titanium dioxide.

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Section: Characterization Of the Solidsmentioning

confidence: 78%

Section: Characterization Of the Solidsmentioning

confidence: 99%

Kaolinite/TiO2/cobalt(II) Tetracarboxymetallophthalocyanine Nanocomposites as Heterogeneous Photocatalysts for Decomposition of Organic Pollutants Trimethoprim, Caffeine and Prometryn

Silva¹,

Ribeiro²,

Nassar³

et al. 2019

J. Braz. Chem. Soc.

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“…On one side, surface oxygens of the tetrahedral sheet are present, while the other side contains exposed inner-surface hydroxyls. The latter are susceptible to grafting reactions with, for example, alcohols (Matusik et al , 2012; Cheng et al , 2015), diols (Gardolinski & Lagaly, 2005a), aminoalcohols (Letaief & Detellier, 2007; Koteja & Matusik, 2015) and organic acids (da Silva et al , 2016). These grafted compounds have been tested in a wide variety of applications (Dedzo & Detellier, 2016).…”

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confidence: 99%

Preparation of azobenzene-intercalated kaolinite and monitoring of the photoinduced activity

Koteja

Matusik

2019

Clay miner.

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Systems consisting of layered structures and photoactive molecules have been studied extensively. The structures of resulting complexes may be controlled by UV–Vis radiation, which subsequently affects their materials properties. This study describes a synthesis route for obtaining a photoresponsive kaolinite intercalation compound. The material was prepared by co-intercalating azobenzene and benzylalkylammonium chlorides into a methoxy form of kaolinite. The resultant materials possessed large basal spacing values in the range of 45–55 Å. The UV–Vis and Fourier-transform infrared spectroscopy analyses confirmed the reversible photoisomerization of azobenzene upon exposure to UV and Vis radiation. This phenomenon was significantly influenced by the type and amount of co-intercalated molecules. Upon multiple trans–cis conversions, the azobenzene partially evaporated. For the first time, a kaolinite-based material was prepared that exhibited photochromic behaviour upon UV and Vis irradiation.

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“…Clay minerals are easily available and, therefore, relatively cheap. Moreover, various methods of their catalytic activation, including acid treatment [88], delamination [89], and intercalation with inorganic pillars [90,91], have been reported in the scientific literature.…”

Section: Clay Mineral-based Catalystsmentioning

confidence: 99%

Dehydration of Methanol to Dimethyl Ether—Current State and Perspectives

Chmielarz

2024

Catalysts

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The main groups of catalytic materials used in the conversion of methanol to dimethyl ether (the MTD process) were presented with respect to their advantages, disadvantages, and the methods of their modifications, resulting in catalysts with improved activity, selectivity, and stability. In particular, the effects of strength, surface concentration, and the type of acid sites, the porous structure and morphology of the catalytic materials, the role of catalyst activators, and others, were considered. The prosed mechanisms of the MTD process over various types of catalysts are presented. Moreover, the advantages of membrane reactors for the MTD process are presented and analysed. The perspectives in the development of effective catalysts for the dehydration of methanol to dimethyl ether are presented and discussed.

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Influence of physical/chemical treatments to delamination of nanohybrid kaolinite-dipicolinate

Cited by 9 publications

References 32 publications

Kaolinite/TiO2/cobalt(II) Tetracarboxymetallophthalocyanine Nanocomposites as Heterogeneous Photocatalysts for Decomposition of Organic Pollutants Trimethoprim, Caffeine and Prometryn

Kaolinite/TiO2/cobalt(II) Tetracarboxymetallophthalocyanine Nanocomposites as Heterogeneous Photocatalysts for Decomposition of Organic Pollutants Trimethoprim, Caffeine and Prometryn

Preparation of azobenzene-intercalated kaolinite and monitoring of the photoinduced activity

Dehydration of Methanol to Dimethyl Ether—Current State and Perspectives

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