Role of F− in the hydrolysis–condensation mechanisms of silicon alkoxide Si(OCH3)4: a DFT investigation

Cheng, Xueli; Zhao, Yulong; Liu, Yongjun; Li, Feng

doi:10.1039/c3nj41140k

Cited by 11 publications

(10 citation statements)

References 45 publications

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“…Hydrolysis and condensation of metal oxide precursors (e.g., metal alkoxide) are essential for the formation of inorganic oxide matrixes. In case of silica, the sol‐gel reactions cause polycondensation of the precursor (e.g., silicon alkoxides) and subsequent shrinkage of the silicate frameworks . As shown in Figure , condensation reactions of silanol (Si−OH) and alkoxy (Si−OR) groups (R; alkyl group) leads to the increase of siloxane (Si−O−Si) networks, resulting in the shrinkage of frameworks .…”

Section: Molecular Mechanism Inducing Shrinkagementioning

confidence: 99%

“…In case of silica, the sol-gel reactions cause polycondensation of the precursor (e.g.,s ilicon alkoxides) and subsequents hrinkage of the silicate frameworks. [31,32] As shown in Figure 1, condensation reactions of silanol (SiÀOH) and alkoxy (SiÀOR) groups (R;a lkyl group) leads to the increase of siloxane (SiÀOÀSi)n etworks, resultingi nt he shrinkage of frameworks. [33] Scanning electron microscopy (SEM) clearly shows the change from spherical to oval shapes of pores by anisotropic shrinkage of ap orouss ilica film.…”

Section: Moleculeinteraction Of Oxidementioning

confidence: 99%

“…PO 2 (OH) 2 ,P O 3 (OH), and PO 4 units are observed at around À7, À10, and À27 ppm, respectively. [40,41] As shown in Figure 4, the 31 PM AS NMR spectra of as urfactant-assisted poroust itanium phosphate show that the peak is shifted to the highermagnet- ic field with the formation of TiÀOÀPb onds after solvent-extraction and subsequent calcination. [42]…”

Section: Molecular Interaction Of Phosphatementioning

confidence: 99%

“…31 PM AS NMR spectraof( a) as-synthesized, (b) solvent-extracted, and (c) subsequentlyc alcined( 540 8C) titanium phosphates (reproduced with permission from Ref [42]…”

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confidence: 99%

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Analytical Understanding of the Materials Design with Well‐Described Shrinkages on Multiscale

Dutta

et al. 2018

Chemistry A European J

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Shrinkages derived from condensation of frameworks are one of the significant steps for fabricating demanded materials having unique morphologies and properties. Enormous efforts have been dedicated to understanding their mechanisms that are quite useful for the materials design. In this context, diversified measuring and observing tools have been facilitated to evaluate structural contractions and corresponding driving forces. All of the investigations are crucial to encourage the utilization of such shrinkages for the precise design of nanomaterials. In this review, we summarize significant works how to analyze shrinkages in multiscale during the synthesis of materials, which will be useful as a follow-up review to our latest contribution. Well-defined porous materials are also selected as a good candidate for understanding well-described shrinkages. This review aims to provide a detailed glimpse of the development of analyses on shrinking behaviors in multiscale for the materials design. Shrinking degree and direction in multiscale, which are driven by condensation of frameworks, are predominant for understanding and/or predicting final nanostructures of materials after shrinkages.

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Section: Molecular Mechanism Inducing Shrinkagementioning

confidence: 99%

Section: Moleculeinteraction Of Oxidementioning

confidence: 99%

Section: Molecular Interaction Of Phosphatementioning

confidence: 99%

“…31 PM AS NMR spectraof( a) as-synthesized, (b) solvent-extracted, and (c) subsequentlyc alcined( 540 8C) titanium phosphates (reproduced with permission from Ref [42]…”

mentioning

confidence: 99%

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Analytical Understanding of the Materials Design with Well‐Described Shrinkages on Multiscale

Dutta

et al. 2018

Chemistry A European J

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“…In order to further explore the surface compositions and chemical state of the sample, X-ray photoelectron spectroscopy (XPS) was acquired (Figure 3a (Figure 3a), confirming the presence of Bi 3 + . [26][27][28][29] S 2s peak around 225.8 eV can be detected for asprepared Bi 2 S 3 sample ( Figure S1 in the Supporting Information). [30] The two peaks observed between Bi 4f 5/2 and Bi 4f 7/2 are related to S 2p 1/2 at 162.7 eV and S 2p 3/2 at 161.3 eV (Figure 3b).…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal Synthesis of Urchin‐like Bi₂S₃ Nanostructures for Superior Visible‐light‐driven Cr(VI) Removal Capacity

et al. 2018

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In this work, large amounts of urchin‐like Bi2S3 nanostructures assembled from radially oriented nanorods were prepared by a simple hydrothermal method. The as‐prepared Bi2S3 nanostructures possess an orthorhombic crystal structure with a high crystallinity. More importantly, the obtained Bi2S3 nanostructures are spherical architectures composed of large quantities of nanorods with highly active sites. This attractive architecture can provide a large active surface area for photocatalysis. The photodegradation of Cr(VI) under visible light irradiation indicated that 95% of Cr(VI) was degradated within 30 min using the as‐prepared Bi2S3 nanoparticle as a photocatalyst. Further investigations revealed that the pH value of the solution has a significant effect on the photocatalytic reduction ability as well. Significantly, the kinetic constant of urchin‐like Bi2S3 nanostructures for Cr(VI) degradation is about 100 times that of Bi2S3 nanoflowers and commercial P25. Furthermore, the photocurrent of urchin‐like Bi2S3 nanostructures is still higher than that of Bi2S3 nanoflowers. We believed that the urchin‐like Bi2S3 nanostructures are promising materials for Cr(VI) photoreduction.

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N‐Aryl and N‐Alkyl Carbamates from 1 Atmosphere of CO₂

Takeuchi

Chen

Yuan

et al. 2021

Chemistry A European J

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We have successfully isolated and characterized the zinc carbamate complex (phen)Zn(OAc)(OC(=O)NHPh) (1; phen=1,10‐phenanthroline), formed as an intermediate during the Zn(OAc)2/phen‐catalyzed synthesis of organic carbamates from CO2, amines, and the reusable reactant Si(OMe)4. Density functional theory calculations revealed that the direct reaction of 1 with Si(OMe)4 proceeds via a five‐coordinate silicon intermediate, forming organic carbamates. Based on these results, the catalytic system was improved by using Si(OMe)4 as the reaction solvent and additives like KOMe and KF, which promote the formation of the five‐coordinated silicon species. This sustainable and effective method can be used to synthesize various N‐aryl and N‐alkyl carbamates, including industrially important polyurethane raw materials, starting from CO2 under atmospheric pressure.

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Role of F− in the hydrolysis–condensation mechanisms of silicon alkoxide Si(OCH3)4: a DFT investigation

Cited by 11 publications

References 45 publications

Analytical Understanding of the Materials Design with Well‐Described Shrinkages on Multiscale

Analytical Understanding of the Materials Design with Well‐Described Shrinkages on Multiscale

Hydrothermal Synthesis of Urchin‐like Bi₂S₃ Nanostructures for Superior Visible‐light‐driven Cr(VI) Removal Capacity

N‐Aryl and N‐Alkyl Carbamates from 1 Atmosphere of CO₂

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Role of F− in the hydrolysis–condensation mechanisms of silicon alkoxide Si(OCH3)4: a DFT investigation

Cited by 11 publications

References 45 publications

Analytical Understanding of the Materials Design with Well‐Described Shrinkages on Multiscale

Analytical Understanding of the Materials Design with Well‐Described Shrinkages on Multiscale

Hydrothermal Synthesis of Urchin‐like Bi2S3 Nanostructures for Superior Visible‐light‐driven Cr(VI) Removal Capacity

N‐Aryl and N‐Alkyl Carbamates from 1 Atmosphere of CO2

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Product

Resources

About

Hydrothermal Synthesis of Urchin‐like Bi₂S₃ Nanostructures for Superior Visible‐light‐driven Cr(VI) Removal Capacity

N‐Aryl and N‐Alkyl Carbamates from 1 Atmosphere of CO₂