The University of Southampton
University of Southampton Institutional Repository

Demonstration of visible light activated photocatalytic self-cleaning by thin films of perovskite tantalum and niobium oxynitrides

Demonstration of visible light activated photocatalytic self-cleaning by thin films of perovskite tantalum and niobium oxynitrides
Demonstration of visible light activated photocatalytic self-cleaning by thin films of perovskite tantalum and niobium oxynitrides

Metal oxynitrides adopting the perovskite structure have been shown to be visible light-activated photocatalysts, and therefore, they have potential as self-cleaning materials where surface organic pollutants can be removed by photomineralization. In this work, we establish a route for the deposition of thin films for seven perovskite oxynitrides, CaTaO2N, SrTaO2N, BaTaO2N, LaTaON2, EuTaO2N, SrNbO2N, and LaNbON2, on quartz and alumina substrates using dip-coating of a polymer gel to form an amorphous oxide precursor film, followed by ammonolysis. The initially deposited oxide films were annealed at 800 °C, followed by ammonolysis at temperatures from 850 to 1000 °C. The perovskite oxynitride thin films were characterized using XRD and EDX, with band gaps determined using Tauc plots derived from UV-vis spectroscopic data. A cobalt oxide co-catalyst was deposited onto each film by drop casting, and the photocatalytic activity assessed under visible light using dichloroindophenol dye degradation in the presence of a sacrificial oxidant. The light source used was a solar simulator equipped with a 400 nm cut-off filter. The dye degradation test demonstrated photocatalytic activity in all samples except EuTaO2N and BaTaO2N. The three most active samples were SrNbO2N, CaTaO2N, and SrTaO2N. The cobalt oxide loading was optimized for these three films and found to be 0.3 μg cm-2. Further, catalytic tests were conducted using stearic acid degradation, and this found the film of SrNbO2N with the cobalt oxide co-catalyst to be the most active for complete mineralization of this model pollutant.

AACVD, chemical vapor deposition, mixed anion, oxynitride, perovskite, photocatalysis, self-cleaning, thin film
1944-8244
33603-33612
Iborra Torres, Antonio
231fb0fc-78fd-40ea-9ebd-0bb0c6131e71
Kulak, Alexander N.
b5932a7d-a10a-4862-ac32-a7a1e08be88b
Palgrave, Robert G.
6b26b39c-1da4-4937-beaa-c0848840b7bd
Hyett, Geoffrey
4f292fc9-2198-4b18-99b9-3c74e7dfed8d
Iborra Torres, Antonio
231fb0fc-78fd-40ea-9ebd-0bb0c6131e71
Kulak, Alexander N.
b5932a7d-a10a-4862-ac32-a7a1e08be88b
Palgrave, Robert G.
6b26b39c-1da4-4937-beaa-c0848840b7bd
Hyett, Geoffrey
4f292fc9-2198-4b18-99b9-3c74e7dfed8d

Iborra Torres, Antonio, Kulak, Alexander N., Palgrave, Robert G. and Hyett, Geoffrey (2020) Demonstration of visible light activated photocatalytic self-cleaning by thin films of perovskite tantalum and niobium oxynitrides. ACS Applied Materials and Interfaces, 12 (30), 33603-33612. (doi:10.1021/acsami.0c05008).

Record type: Article

Abstract

Metal oxynitrides adopting the perovskite structure have been shown to be visible light-activated photocatalysts, and therefore, they have potential as self-cleaning materials where surface organic pollutants can be removed by photomineralization. In this work, we establish a route for the deposition of thin films for seven perovskite oxynitrides, CaTaO2N, SrTaO2N, BaTaO2N, LaTaON2, EuTaO2N, SrNbO2N, and LaNbON2, on quartz and alumina substrates using dip-coating of a polymer gel to form an amorphous oxide precursor film, followed by ammonolysis. The initially deposited oxide films were annealed at 800 °C, followed by ammonolysis at temperatures from 850 to 1000 °C. The perovskite oxynitride thin films were characterized using XRD and EDX, with band gaps determined using Tauc plots derived from UV-vis spectroscopic data. A cobalt oxide co-catalyst was deposited onto each film by drop casting, and the photocatalytic activity assessed under visible light using dichloroindophenol dye degradation in the presence of a sacrificial oxidant. The light source used was a solar simulator equipped with a 400 nm cut-off filter. The dye degradation test demonstrated photocatalytic activity in all samples except EuTaO2N and BaTaO2N. The three most active samples were SrNbO2N, CaTaO2N, and SrTaO2N. The cobalt oxide loading was optimized for these three films and found to be 0.3 μg cm-2. Further, catalytic tests were conducted using stearic acid degradation, and this found the film of SrNbO2N with the cobalt oxide co-catalyst to be the most active for complete mineralization of this model pollutant.

Text
Perovskite Oxynitride Hyett AMandI V3 - Accepted Manuscript
Download (5MB)

More information

Accepted/In Press date: 30 June 2020
e-pub ahead of print date: 30 June 2020
Published date: 29 July 2020
Additional Information: Funding Information: Antonio Iborra-Torres thanks the EPSRC for provision of funding for his doctorate. Publisher Copyright: Copyright © 2020 American Chemical Society.
Keywords: AACVD, chemical vapor deposition, mixed anion, oxynitride, perovskite, photocatalysis, self-cleaning, thin film

Identifiers

Local EPrints ID: 442285
URI: http://eprints.soton.ac.uk/id/eprint/442285
ISSN: 1944-8244
PURE UUID: 9e66f7e2-45b4-43c6-a158-f7f4e9391946
ORCID for Geoffrey Hyett: ORCID iD orcid.org/0000-0001-9302-9723

Catalogue record

Date deposited: 10 Jul 2020 16:31
Last modified: 17 Mar 2024 05:43

Export record

Altmetrics

Contributors

Author: Antonio Iborra Torres
Author: Alexander N. Kulak
Author: Robert G. Palgrave
Author: Geoffrey Hyett ORCID iD

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×