ChemInform Abstract: Ferroelastic Layered Perovskites M(I)(An‐1NbnO3n+1 ) with n: 2, 3, and 4.

Dion, Michel; Ganne, M.; Tournoux, M.

doi:10.1002/chin.198631031

Cited by 34 publications

(65 citation statements)

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“…Only one case with CN = 11 was found, and it was omitted from all subsequent statistics. This case refers to Ca3 in a perovskite-type structure: CsCa2Nb3Olo (Dion, Ganne & Tournoux, 1984). In the same structure there are two other Ca atoms with CN = 8 and one with CN = 9.…”

Section: Experimental Methodsmentioning

confidence: 99%

On metal–oxygen coordination. A statistical method to determine coordination number. I. Calcium

Chiari¹

1990

Acta Crystallogr Sect B

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The environment around the Ca cation for compounds involving bonded oxygen has been studied for 254 inorganic structures containing a total of 368 polyhedra. Selection was made on the basis of the accuracy of the structural data. The coordination number (CN) was assigned using the criteria of maximum gap in the Ca--O distances and balanced bond-valence sums for Ca, but 32 cases were still difficult to assign unambiguously. A series of variables related to the Ca---O distances were calculated and averaged for each value of CN. The Gaussian curves representing the distribution of these variables for each CN overlap strongly. By way of contrast, the volume of the coordination polyhedra (Vol) showed well separated curves. Statistical analysis was applied to the set of structures with known CN, with seven variables and then with Vol alone, which seems to discriminate between the various CN groups equally well. A strong linear dependence was found for CN versus Vol. A method is proposed to assign CN in uncertain cases based on the equation: CN = 0.197 (2)Vol + 2.83 (5). Application of this equation to the unassigned cases compares favourably with discriminant analysis using the larger set of variables.

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Section: Experimental Methodsmentioning

confidence: 99%

On metal–oxygen coordination. A statistical method to determine coordination number. I. Calcium

Chiari¹

1990

Acta Crystallogr Sect B

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“…The characteristic sequence of adjacent perovskite layer ((Ca B O )U) stacking is given by a distinct shift vector (de"ned as sh) of perovskite layers in the direction perpendicular to the c-or a-axis that depends on the setting of the appropriate space group. This shift depends on the nature/size of the alkali metal cations (1,19,20). For example, in the case of the large alkali metals like Rb and Cs, alternating perovskite slabs are stacked together without any shift: sh"(0, 0, 0) (1,19).…”

Section: Structure Descriptionmentioning

confidence: 98%

“…Therefore, the structural data of CsCa Ta O were used as starting parameters for the Rietveld re"nement. The "nal atomic positions are given in Table 2 (20).…”

Section: And Cssrmentioning

confidence: 99%

Synthesis, Structure, and Electrical Conductivity of A′[A2B3O10](A′=Rb, Cs; A=Sr, Ba; B=Nb, Ta): New Members of Dion–Jacobson-Type Layered Perovskites

Thangadurai

Schmid‐Beurmann²,

Weppner

2001

Journal of Solid State Chemistry

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“…13) RuddlesdenPopper phases have two interlayer cations per formula unit and possess twice the interlayer charge density of the DionJacobson phase. 14) Aurivillius phase are intergrowths of perovskite and bismuth oxide and have a covalent network of Bi 2 O 2 2+ between the two-dimensional perovskite slabs.…”

Section: )11)mentioning

confidence: 99%

Preparation and phase transformation of Ag or Bi ion-exchanged layered niobate perovskite and their photocatalytic properties

Takei

Miura

et al. 2015

J. Ceram. Soc. Japan

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Ag-intercalated and Bi-intercalated layered perovskite were fabricated by ion-exchanged process. The XRD and XPS confirm the phase transformation of the Ag-ion exchanged layered perovskite from DionJacobson to RuddlesdenPopper phase by heating at higher than 200°C. In the case of Bi ion-exchange perovskite, the product remained DionJacobson phase during the heat treatment. For the Ag-intercalated sample, RuddlesdenPopper type photocatalyst by heating at 500°C can degrade 20 ppm phenol solution to 6 ppm in 3 h under Xe light, which has superior photocatalytic activity to DionJacobson phase Ag 0.67 H 0.33 LaNb 2 O 7 . For the Bi-intercalated sample, DionJacobson type photocatalyst can degrade phenol from 20 to 12 ppm in 3 h. From first principle DFT simulation, high photocatalytic activity may be due to the new Ag 4d, O 2p and Nb 4d hybridized band at the highest of the valence band for Ag-included, and to the new Bi 6p band at the lowest of the conduction band for Biincluded samples.©2015 The Ceramic Society of Japan. All rights reserved.Key-words : Photocatalyst, Layered perovskite, Ion-exchange, Phenol degradation, Phase transformation, DOS calculation [Received May 12, 2015; Accepted June 22, 2015] Concerning the global environmental issues and energy crisis, photocatalysis technology using semiconductors has been attracting more and more consideration. 1)3) Over the past several decades, researchers have been searched for effective methods for chemical waste removal. Several contaminants are of particular threatened to the health of human being, such as phenolic compounds, various dyes, etc. 4)7) However, removal of phenol presents serious challenges, because this molecule is not biodegradable and could hardly undergo direct photolysis by sunlight or removed by conventional water treatment processes. Layered perovskite as an ideal green chemistry photocatalyst is undoubtedly advantageous over the other conventional catalyst. 8)11)Layered perovskites are intergrowths of perovskite and other structures, and they consist of two-dimensional perovskite slabs interleaved with cations or cationic structural units.12) The Dion Jacobson series of layered perovskites has one interlayer cation per formula unit. 18) On the basis of Li and Lin's results, the present work reports a study on the photocatalytic performance of interlayered perovskite from a layered perovskite structural oxides HLaNb 2 O 7 as host, Ag or Bi as guest by control of top in the valence band. Therefore, we study the hybridization of layered niobate perovskite with Ag or Bi in detail. Such structure is expected to not only change the valence band but also inhibit the recombination of charge carriers effectively, and the photocatalytic activity of semiconductor can be enhanced.All reagents were purchased from Kanto kagaku Ltd. Japan. Layered compound RbLaNb 2 O 7 was synthesized by a solidstate reaction at 1000°C in air for 6 h, using an intimate mixture of reagent-grade Rb 2 CO 3 , La 2 O 3 , Nb 2 O 5 with a mole ratio of Rb:La:Nb = 1.25:1:2 as s...

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ChemInform Abstract: Ferroelastic Layered Perovskites M(I)(A_n‐1Nb_nO_3n+1 ) with n: 2, 3, and 4.

Abstract: The study of the n: 3 members of the layered perovskite‐like families with M(I): Na, K, Rb, Cs; A: Nd, Ca) has been completed.

Cited by 34 publications

References 0 publications

On metal–oxygen coordination. A statistical method to determine coordination number. I. Calcium

On metal–oxygen coordination. A statistical method to determine coordination number. I. Calcium

Synthesis, Structure, and Electrical Conductivity of A′[A2B3O10](A′=Rb, Cs; A=Sr, Ba; B=Nb, Ta): New Members of Dion–Jacobson-Type Layered Perovskites

Preparation and phase transformation of Ag or Bi ion-exchanged layered niobate perovskite and their photocatalytic properties

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