Volume 227, 2021

Computational design of graphitic carbon nitride photocatalysts for water splitting

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 phosphorus, 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 1.6 eV, corresponding to red light); the doped material has the valence band position suitable for water oxidation. Our computational study shows that chemical modification of g-C3N4 is a powerful method to tune this material’s electronic properties and improve its photocatalytic activity.

Graphical abstract: Computational design of graphitic carbon nitride photocatalysts for water splitting

Associated articles

Supplementary files

Article information

Article type
Paper
Submitted
24 Dec 2019
Accepted
28 Jan 2020
First published
28 Jan 2020

Faraday Discuss., 2021,227, 341-358

Computational design of graphitic carbon nitride photocatalysts for water splitting

G. O. Hartley and N. Martsinovich, Faraday Discuss., 2021, 227, 341 DOI: 10.1039/C9FD00147F

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