Hartley, G.O. and Martsinovich, N. orcid.org/0000-0001-9226-8175 (2021) Computational design of graphitic carbon nitride photocatalysts for water splitting. Faraday Discussions, 227. pp. 341-358. ISSN 1359-6640
Abstract
A series of structures based on graphitic carbon nitride (g-C3N4), a layered material composed of linked carbon-nitrogen heterocycles arranged in a plane, were investigated by density functional theory calculations. g-C3N4 is a semiconductor that absorbs UV light and visible light at the blue end of the visible spectrum, and is widely studied as a photocatalyst for water splitting; however, its photocatalytic efficiency is limited by its poor light-harvesting ability and low charge mobilities. Modifications to the g-C3N4 structure could greatly improve its optical and electronic properties and its photocatalytic efficiency. In this work, the g-C3N4 structure was modified by replacing the nitrogen linker with heteroatoms (phosphorus, boron) or aromatic groups (benzene, s-triazine and substituted benzenes). Two-dimensional (2D) sheets and three-dimensional (3D) multilayer structures with different stacking types were modelled. Several new structures were predicted to have electronic properties superior to g-C3N4 for use as water splitting photocatalysts. In particular, introduction of benzene and s-triazine groups led to band gaps smaller than in the standard g-C3N4 (down to 2.4 eV, corresponding to green light). Doping with boron in the linker positions dramatically reduced the band gap (to 1.7 eV, corresponding to red light); the doped material had the valence band position suitable for water oxidation. Our computational study showed that chemical modification of g-C3N4 is a powerful method to tune this material’s electronic properties and improve its photocatalytic activity.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2020 The Royal Society of Chemistry. This is an author-produced version of a paper subsequently published in Faraday Discussions. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
|
Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Chemistry (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 11 Mar 2020 09:19 |
Last Modified: | 06 Dec 2021 16:27 |
Status: | Published |
Publisher: | Royal Society of Chemistry (RSC) |
Refereed: | Yes |
Identification Number: | 10.1039/c9fd00147f |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:158309 |