Issue 4, 2019

Enhanced charge separation in g-C3N4–BiOI heterostructures for visible light driven photoelectrochemical water splitting

Abstract

Heterojunctions of the low bandgap semiconductor bismuth oxyiodide (BiOI) with bulk multilayered graphitic carbon nitride (g-C3N4) and few layered graphitic carbon nitride sheets (g-C3N4-S) are synthesized and investigated as an active photoanode material for sunlight driven water splitting. HR-TEM and elemental mapping reveals formation of a unique heterostructure between BiOI platelets and the carbon nitride (g-C3N4 and g-C3N4-S) network that consisted of dendritic BiOI nanoplates surrounded by g-C3N4 sheets. The presence of BiOI in g-C3N4-S/BiOI and g-C3N4-S/BiOI nanocomposites extends the visible light absorption profile from 500 nm up to 650 nm. Due to excellent charge separation in g-C3N4/BiOI and g-C3N4-S/BiOI, evident from quenching of the carbon nitride photoluminescence (PL) and a decrease in the PL lifetime, a significant increase in photoelectrochemical performance is observed for both types of g-C3N4–BiOI heterojunctions. In comparison to heterojunctions of bulk g-C3N4 with BiOI, the nanocomposite consisting of few layered sheets of g-C3N4 and BiOI exhibits higher photocurrent density due to lower recombination in few layered sheets. A synergistic trap passivation and charge separation is found to occur in the g-C3N4-S/BiOI nanocomposite heterostructure which results in a higher photocurrent and a lower charge transfer resistance.

Graphical abstract: Enhanced charge separation in g-C3N4–BiOI heterostructures for visible light driven photoelectrochemical water splitting

Supplementary files

Article information

Article type
Paper
Submitted
01 okt 2018
Accepted
06 jan 2019
First published
07 jan 2019
This article is Open Access
Creative Commons BY-NC license

Nanoscale Adv., 2019,1, 1460-1471

Enhanced charge separation in g-C3N4–BiOI heterostructures for visible light driven photoelectrochemical water splitting

K. M. Alam, P. Kumar, P. Kar, U. K. Thakur, S. Zeng, K. Cui and K. Shankar, Nanoscale Adv., 2019, 1, 1460 DOI: 10.1039/C8NA00264A

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, 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 commercial 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