Achieving high photocatalytic NOx removal activity using a Bi/BiOBr/TiO2 composite photocatalyst
File(s)
Published version
Author(s)
Alimard, Paransa
Gong, Chen
Itskou, Ioanna
Kafizas, Andreas
Type
Journal Article
Abstract
Fossil fuel combustion generates nitrogen oxides (NO + NO2 = NOx), which pose threats to the environment and human health. Although commercial products containing titanium dioxide (TiO2) can remedy NOx pollution by photocatalysis, they only function in the ultraviolet (UV). On the other hand, bismuth oxybromide (BiOBr) is active in the visible. BiOBr is stable, affordable, and non-toxic, making it an appealing alternative. In addition, nanoparticulate Bi metal can further enhance visible light absorption through its surface plasmon properties and charge carrier lifetime by spatially separating charge. In this study, to enhance the visible-light activity of TiO2-based photocatalysts for NOx pollution, a composite of Bi-decorated BiOBr/TiO2 was synthesised using a solvothermal method across varying the Ti/Bi atomic ratio (0.2, 2.2, 4.4, and 6.6), and synthesis duration (6h, 12h, and 18h). The photocatalytic performance of the synthesised composites for NO gas removal was investigated using an adapted ISO method (22197–1:2016). Analysis showed that the preferential growth of the (010) crystal facet in BiOBr and the presence of Bi metal both play an important role in the superior photocatalytic activity seen in our Bi-decorated BiOBr/TiO2 composite. The composites were characterised using X-ray diffraction (XRD), attenuated total reflectance - Fourier transform infrared spectroscopy (ATR-FTIR), high-resolution scanning electron microscopy (HR-SEM), UV–Vis diffuse reflectance (DRS) spectroscopy, transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Brunauer-Emmett-Teller (BET) analysis, thermogravimetric analysis (TGA), and diffuse reflectance transient absorption spectroscopy (DR-TAS). Our research shows that the Bi/BiOBr–TiO2 composite synthesised through a 12h solvothermal method with a Ti/Bi atomic ratio of 4.4 exhibits the highest photocatalytic performance towards both NO and NO2 oxidation; with 32.8% and 54.9% NO removal and 15.1% and 29.5% NO2 under visible and UV lamps, respectively.
Date Issued
2024-11-01
Date Acceptance
2024-11-09
Citation
Chemosphere, 2024, 368
ISSN
0045-6535
Publisher
Elsevier
Journal / Book Title
Chemosphere
Volume
368
Copyright Statement
© 2024 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/39549966
PII: S0045-6535(24)02628-6
Subjects
Air purification
Bismuth oxybromide (BiOBr)
Charge carrier dynamics
Composite
Photocatalytic NO(x) removal
Surface plasmon resonance (SPR)
Titanium dioxide (TiO(2))
Titanium
Catalysis
Bismuth
Nitrogen Oxides
Photochemical Processes
Air Pollutants
Ultraviolet Rays
Light
Publication Status
Published
Coverage Spatial
England
Article Number
143728
Date Publish Online
2024-11-21