Issue 2, 2023

Improved photocatalytic activity of ZnO-[10%]BiOI and ZnO-[10%]WO3 heterostructure in the destruction of 2-chlorobiphenyl

Abstract

A series of photocatalysts and heterojunction composites comprising ZnO, WO3, and BiOI with different loadings of WO3 and BiOI into ZnO was synthesized and applied for the destruction of 2-chlorobiphenyl (2CBP). The surface morphologies and elemental analysis of the as-synthesized composites were determined using a Carl Zeiss Sigma FE-SEM equipped with an Oxford X-act EDS; optical studies were conducted using a UV 1800 Shimadzu UV-vis spectrophotometer. The X-ray diffraction measurements were made with a Bruker D2 XRD instrument, while the BET surface area measurements, BJH pore size distribution, and isotherms were obtained using a Micrometrics TriStar 3000 instrument. The ZnO-[10%]BiOI heterostructure exhibited a superior photocatalytic activity in this study. The degradation reactions were fitted to the pseudo-first and second order kinetic models in order to exploit the kinetic process of the photodegradation reaction. The ZnO-[10%]BiOI hetero-photocatalyst showed the highest rate constants of 0.0054 min−1 and 0.0086 min−1 in both the first and second order kinetic models, respectively. When compared to undoped ZnO, the rate constant of the ZnO-[10%]BiOI heterostructure was observed to be nearly 5-fold higher, demonstrating the superior catalytic performance of the as-prepared ZnO-[10%]BiOI hetero-structured photocatalyst. All the photocatalysts and heterostructures showed increased rate constants in the second-order reaction kinetics model except for BiOI and ZnO-[5%]WO3, whose rate constants decreased from 0.0046 to 0.0041 min−1 and 0.0036 to 0.0029 min−1, respectively. The kinetic data show that it requires 128.4 min for the measured 2CBP concentration to be halved to the initial concentration when ZnO-[10%]BiOI is applied. A charge separation degradation mechanism is proposed to describe the process. The findings from this study suggest that ZnO-[10%]BiOI can potentially be used as an efficient and effective catalyst for the degradation of recalcitrant organic pollutants in water.

Graphical abstract: Improved photocatalytic activity of ZnO-[10%]BiOI and ZnO-[10%]WO3 heterostructure in the destruction of 2-chlorobiphenyl

Supplementary files

Article information

Article type
Paper
Submitted
14 Sep 2022
Accepted
23 Dec 2022
First published
26 Dec 2022
This article is Open Access
Creative Commons BY-NC license

Environ. Sci.: Adv., 2023,2, 325-338

Improved photocatalytic activity of ZnO-[10%]BiOI and ZnO-[10%]WO3 heterostructure in the destruction of 2-chlorobiphenyl

D. C. Ashiegbu, N. Moloto and H. Potgieter, Environ. Sci.: Adv., 2023, 2, 325 DOI: 10.1039/D2VA00222A

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