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.
|Журнал||Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials|
|Состояние||Опубликовано - 1 июн 2017|