Please use this identifier to cite or link to this item: http://dx.doi.org/10.14279/depositonce-6217
Main Title: The contrasting effect of the Ta/Nb ratio in (111)-layered B-site deficient hexagonal perovskite Ba5Nb4-xTaxO15 crystals on visible-light-induced photocatalytic water oxidation activity of their oxynitride derivatives
Author(s): Hojamberdiev, Mirabbos
Bekheet, Maged F.
Zahedi, Ehsan
Wagata, Hajime
Vequizo, Junie Jhon M.
Yamakata, Akira
Yubuta, Kunio
Gurlo, Aleksander
Domen, Kazunari
Teshima, Katsuya
Type: Article
Language Code: en
Abstract: The effect of the Ta/Nb ratio in the (111)-layered B-site deficient hexagonal perovskite Ba5Nb4-xTaxO15 (0 <= x <= 4) crystals grown by a KCl flux method on visible-light-induced photocatalytic water oxidation activity of their oxynitride derivatives BaNb1-xTaxO2N (0 <= x <= 1) was investigated. The Rietveld refinement of X-ray data revealed that all Ba5Nb4-xTaxO15 samples were well crystallized in the space group P (3) over bar m1 (no. 164). Phase-pure BaNb1-xTaxO2N (0 <= x <= 1) porous structures were obtained by nitridation of the flux-grown oxide crystals at 950 degrees C for 20, 25, 30, 35, and 40 h, respectively. The absorption edge of BaNb1-xTaxO2N (0 <= x <= 1) was slightly shifted from 720 to 690 nm with the increasing Ta/Nb ratio. The O-2 evolution rate gradually progressed and reached the highest value (127.24 mu mol in the first 2 h) with the Ta content up to 50 mol% but decreased at 75 and 100 mol% presumably due to the reduced specific surface area and high density of structural defects, such as grain boundaries acting as recombination centers, originated from high-temperature nitridation for prolonged periods. Transient absorption spectroscopy provided evidence for the effect of the Ta/Nb ratio on the behavior and energy states of photogenerated charge carriers, indicating a direct correlation with photocatalytic water oxidation activity of BaNb1-xTaxO2N.
URI: https://depositonce.tu-berlin.de//handle/11303/6878
http://dx.doi.org/10.14279/depositonce-6217
Issue Date: 2016
Date Available: 24-Oct-2017
DDC Class: 540 Chemie und zugeordnete Wissenschaften
Usage rights: Terms of German Copyright Law
Journal Title: Dalton transactions
Publisher: Royal Society of Chemistry
Publisher Place: Cambridge
Volume: 45
Issue: 31
Publisher DOI: 10.1039/c6dt02095j
Page Start: 12559
Page End: 12568
EISSN: 1477-9234
ISSN: 1477-9226
Notes: Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
Appears in Collections:Fachgebiet Keramische Werkstoffe » Publications

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