Issue 23, 2020

Facet engineering of LaNbON2 transformed from LaKNaNbO5 for enhanced photocatalytic O2 evolution

Abstract

LaNbON2 absorbs visible light up to approximately 750 nm, one of the longest λmax values among Nb-based oxynitrides, but its photocatalytic water oxidation activity remains negligible owing partly to the exposure of inactive facets during thermal nitridation. Herein, LaNbON2 with exposed metastable {010} facets was prepared by nitriding plate-like LaKNaNbO5. During nitridation, the transformation of LaKNaNbO5 into LaNbON2 along the [010] direction occurred owing to their matching crystal structures, resulting in {010} facets exposed on the surface of plate-like LaNbON2. DFT calculations revealed that the {010} facets have a higher surface energy than the {100} facets of conventional LaNbON2. The exposure of such metastable {010} facets appears to have improved electron transfer from the interior of LaNbON2 to its surface along the [010] direction. After loading a CoOx cocatalyst, plate-like LaNbON2 exhibited enhanced photocatalytic O2 evolution activity with an apparent quantum yield (AQY) of 0.82% while conventional LaNbON2 was almost inactive. This is probably due to the small effective mass of electrons along the [010] direction and the low defect densities in LaNbON2 crystals after a mild nitridation. This work provides a novel transformation strategy yielding LaNbON2 with low defect densities and exposed metastable facets, thus exhibiting unique photocatalytic activity.

Graphical abstract: Facet engineering of LaNbON2 transformed from LaKNaNbO5 for enhanced photocatalytic O2 evolution

Supplementary files

Article information

Article type
Paper
Submitted
07 Feb 2020
Accepted
17 May 2020
First published
18 May 2020

J. Mater. Chem. A, 2020,8, 11743-11751

Facet engineering of LaNbON2 transformed from LaKNaNbO5 for enhanced photocatalytic O2 evolution

X. Wang, T. Hisatomi, J. Liang, Z. Wang, Y. Xiang, Y. Zhao, X. Dai, T. Takata and K. Domen, J. Mater. Chem. A, 2020, 8, 11743 DOI: 10.1039/D0TA01489C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements