TY - JOUR

T1 - Identification of a deleterious phase in photocatalyst based on Cd1-xZnxS/Zn(OH)2 by simulated XRD patterns

AU - Cherepanova, Svetlana

AU - Markovskaya, Dina

AU - Kozlova, Ekaterina

PY - 2017/6/1

Y1 - 2017/6/1

N2 - The X-ray diffraction (XRD) pattern of a deleterious phase in the photocatalyst based on Cd1-xZnxS/Zn(OH)2 contains two relatively intense asymmetric peaks with d-spacings of 2.72 and 1.56 Å. Very small diffraction peaks with interplanar distances of (d) ≃ 8.01, 5.40, 4.09, 3.15, 2.49 and 1.35 Å are characteristic of this phase but not always observed. To identify this phase, the XRD patterns for sheet-like hydroxide β-Zn(OH)2 and sheet-like hydrozincite Zn5(CO3)2(OH)6 as well as for turbostratic hydrozincite were simulated. It is shown that the XRD pattern calculated on the basis of the last model gives the best correspondence with experimental data. Distances between layers in the turbostratically disordered hydrozincite fluctuate around d ≃ 8.01 Å. This average layer-To-layer distance is significantly higher than the interlayer distance 6.77 Å in the ordered Zn5(CO3)2(OH)6 probably due to a deficiency of CO3 2- anions, excess OH- and the presence of water molecules in the interlayers. It is shown by variable-Temperature XRD and thermogravimetric analysis (TGA) that the nanocrystalline turbostratic nonstoichiometric hydrozincite-like phase is quite thermostable. It decomposes into ZnO in air above 473 K.The XRD pattern of a deleterious phase in the photocatalyst based on Cd1-xZnxS/Zn(OH)2 contains two relatively intensive asymmetric peaks with d-spacings of 2.72 and 1.56 Å. To identify this phase, the XRD patterns were calculated for three models: sheet-like β-Zn(OH)2, sheet-like hydrozincite, Zn5(CO3)2(OH)6, and turbostratic hydrozincite. Simulations revealed the formation of a nanocrystalline turbostratic hydrozincite-like phase.

AB - The X-ray diffraction (XRD) pattern of a deleterious phase in the photocatalyst based on Cd1-xZnxS/Zn(OH)2 contains two relatively intense asymmetric peaks with d-spacings of 2.72 and 1.56 Å. Very small diffraction peaks with interplanar distances of (d) ≃ 8.01, 5.40, 4.09, 3.15, 2.49 and 1.35 Å are characteristic of this phase but not always observed. To identify this phase, the XRD patterns for sheet-like hydroxide β-Zn(OH)2 and sheet-like hydrozincite Zn5(CO3)2(OH)6 as well as for turbostratic hydrozincite were simulated. It is shown that the XRD pattern calculated on the basis of the last model gives the best correspondence with experimental data. Distances between layers in the turbostratically disordered hydrozincite fluctuate around d ≃ 8.01 Å. This average layer-To-layer distance is significantly higher than the interlayer distance 6.77 Å in the ordered Zn5(CO3)2(OH)6 probably due to a deficiency of CO3 2- anions, excess OH- and the presence of water molecules in the interlayers. It is shown by variable-Temperature XRD and thermogravimetric analysis (TGA) that the nanocrystalline turbostratic nonstoichiometric hydrozincite-like phase is quite thermostable. It decomposes into ZnO in air above 473 K.The XRD pattern of a deleterious phase in the photocatalyst based on Cd1-xZnxS/Zn(OH)2 contains two relatively intensive asymmetric peaks with d-spacings of 2.72 and 1.56 Å. To identify this phase, the XRD patterns were calculated for three models: sheet-like β-Zn(OH)2, sheet-like hydrozincite, Zn5(CO3)2(OH)6, and turbostratic hydrozincite. Simulations revealed the formation of a nanocrystalline turbostratic hydrozincite-like phase.

KW - Debye simulation

KW - hydrozincite

KW - layered zinc hydroxide

KW - sheet-like particles

KW - turbostratic disorder

KW - AQUEOUS-SOLUTIONS

KW - CRYSTAL-STRUCTURE

KW - NICKEL HYDROXIDES

KW - HYDROGEN EVOLUTION

KW - VISIBLE-LIGHT

KW - HYDROZINCITE

KW - ZINC HYDROXIDE

KW - ETHANOL

KW - SCATTERING

UR - http://www.scopus.com/inward/record.url?scp=85020269489&partnerID=8YFLogxK

U2 - 10.1107/S2052520617001664

DO - 10.1107/S2052520617001664

M3 - Article

AN - SCOPUS:85020269489

VL - 73

SP - 360

EP - 368

JO - Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials

JF - Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials

SN - 2052-5192

IS - 3

ER -