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Ca-assisted nitrogen-rich molecular approach for the synthesis of monodisperse tantalum oxide and (oxy)nitride nanocrystals for visible light-induced water oxidation

Hojamberdiev, Mirabbos and Gonzalo-Juan, Isabel (2016):
Ca-assisted nitrogen-rich molecular approach for the synthesis of monodisperse tantalum oxide and (oxy)nitride nanocrystals for visible light-induced water oxidation.
In: Journal of the Ceramic Society of Japan, The Ceramic Society of Japan, pp. 1052-1055, 124, (10), ISSN 1882-0743,
[Online-Edition: http://dx.doi.org/10.2109/jcersj2.16090],
[Article]

Abstract

The visible-light-induced photocatalytic water oxidation activity without cocatalyst has been demonstrated for the first time on tantalum (oxy)nitride nanocrystals synthesized by a Ca-assisted nitrogen-rich molecular approach. Monodisperse TaON and Ta3N5 nanocrystals were synthesized by using suitable urea /Ta ratios in the presence of Ca2+ions. The as-synthesized (oxy)nitrides are in the form of spherically-shaped and well-defined nanocrystals with an average diameter of ca. 7 nm. Both nanocrystals showed absorption edges in the visible region. The band gap energies of TaON and Ta3N5 nanocrystals were determined from the Tauc’s plots of the UV ­ Vis diffuse reflectance spectra to be 2.27 and 2.08 eV for indirect allowed transitions,respectively. The O2 evolution rate was increased and reached the maximum in the following order: 2.01, 3.32, and 4.66 ̄mol·h¹1 for the samples synthesized with Ca2+/urea molar ratio of 0.10, 0.50, and 0.25, respectively, due to the decrease in the optical band gap. ©2016 The Ceramic Society of Japan. All rights reserved.

Item Type: Article
Erschienen: 2016
Creators: Hojamberdiev, Mirabbos and Gonzalo-Juan, Isabel
Title: Ca-assisted nitrogen-rich molecular approach for the synthesis of monodisperse tantalum oxide and (oxy)nitride nanocrystals for visible light-induced water oxidation
Language: English
Abstract:

The visible-light-induced photocatalytic water oxidation activity without cocatalyst has been demonstrated for the first time on tantalum (oxy)nitride nanocrystals synthesized by a Ca-assisted nitrogen-rich molecular approach. Monodisperse TaON and Ta3N5 nanocrystals were synthesized by using suitable urea /Ta ratios in the presence of Ca2+ions. The as-synthesized (oxy)nitrides are in the form of spherically-shaped and well-defined nanocrystals with an average diameter of ca. 7 nm. Both nanocrystals showed absorption edges in the visible region. The band gap energies of TaON and Ta3N5 nanocrystals were determined from the Tauc’s plots of the UV ­ Vis diffuse reflectance spectra to be 2.27 and 2.08 eV for indirect allowed transitions,respectively. The O2 evolution rate was increased and reached the maximum in the following order: 2.01, 3.32, and 4.66 ̄mol·h¹1 for the samples synthesized with Ca2+/urea molar ratio of 0.10, 0.50, and 0.25, respectively, due to the decrease in the optical band gap. ©2016 The Ceramic Society of Japan. All rights reserved.

Journal or Publication Title: Journal of the Ceramic Society of Japan
Volume: 124
Number: 10
Publisher: The Ceramic Society of Japan
Uncontrolled Keywords: TaON, Ta3N5, Water splitting, Molecular approach, Nanocrystals, Urea
Divisions: 11 Department of Materials and Earth Sciences
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences > Material Science > Dispersive Solids
Date Deposited: 04 Jan 2017 08:54
Official URL: http://dx.doi.org/10.2109/jcersj2.16090
Identification Number: doi:10.2109/jcersj2.16090
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