A Review of Photocatalytic Materials for Urban NOx Remediation
NOx is a pervasive pollutant in urban environments. This review assesses the current state of the art of photocatalytic oxidation materials, designed for the abatement of nitrogen oxides (NOx) in the urban environment, and typically, but not exclusively based on titanium dioxide (TiO<sub>2<...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-05-01
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| Series: | Catalysts |
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| Online Access: | https://www.mdpi.com/2073-4344/11/6/675 |
| _version_ | 1797532655803170816 |
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| author | Hugo Savill Russell Louise Bøge Frederickson Ole Hertel Thomas Ellermann Steen Solvang Jensen |
| author_facet | Hugo Savill Russell Louise Bøge Frederickson Ole Hertel Thomas Ellermann Steen Solvang Jensen |
| author_sort | Hugo Savill Russell |
| collection | DOAJ |
| description | NOx is a pervasive pollutant in urban environments. This review assesses the current state of the art of photocatalytic oxidation materials, designed for the abatement of nitrogen oxides (NOx) in the urban environment, and typically, but not exclusively based on titanium dioxide (TiO<sub>2</sub>). Field trials with existing commercial materials, such as paints, asphalt and concrete, in a range of environments including street canyons, car parks, tunnels, highways and open streets, are considered in-depth. Lab studies containing the most recent developments in the photocatalytic materials are also summarised, as well as studies investigating the impact of physical parameters on their efficiency. It is concluded that this technology may be useful as a part of the measures used to lower urban air pollution levels, yielding ∼2% NOx removal in the immediate area around the surface, for optimised TiO<sub>2</sub>, in some cases, but is not capable of the reported high NOx removal efficiencies >20% in outdoor urban environments, and can in some cases lower air quality by releasing hazardous by-products. However, research into new material is ongoing. The reason for the mixed results in the studies reviewed, and massive range of removal efficiencies reported (from negligible and up to >80%) is mainly the large range of testing practices used. Before deployment in individual environments site-specific testing should be performed, and new standards for lab and field testing should be developed. The longevity of the materials and their potential for producing hazardous by-products should also be considered. |
| first_indexed | 2024-03-10T11:03:22Z |
| format | Article |
| id | doaj.art-5db54a63d01b4700b32960f2106874e9 |
| institution | Directory Open Access Journal |
| issn | 2073-4344 |
| language | English |
| last_indexed | 2024-03-10T11:03:22Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Catalysts |
| spelling | doaj.art-5db54a63d01b4700b32960f2106874e92023-11-21T21:21:00ZengMDPI AGCatalysts2073-43442021-05-0111667510.3390/catal11060675A Review of Photocatalytic Materials for Urban NOx RemediationHugo Savill Russell0Louise Bøge Frederickson1Ole Hertel2Thomas Ellermann3Steen Solvang Jensen4Department of Environmental Science, Aarhus University, DK-4000 Roskilde, DenmarkDepartment of Environmental Science, Aarhus University, DK-4000 Roskilde, DenmarkDepartment of Environmental Science, Aarhus University, DK-4000 Roskilde, DenmarkDepartment of Environmental Science, Aarhus University, DK-4000 Roskilde, DenmarkDepartment of Environmental Science, Aarhus University, DK-4000 Roskilde, DenmarkNOx is a pervasive pollutant in urban environments. This review assesses the current state of the art of photocatalytic oxidation materials, designed for the abatement of nitrogen oxides (NOx) in the urban environment, and typically, but not exclusively based on titanium dioxide (TiO<sub>2</sub>). Field trials with existing commercial materials, such as paints, asphalt and concrete, in a range of environments including street canyons, car parks, tunnels, highways and open streets, are considered in-depth. Lab studies containing the most recent developments in the photocatalytic materials are also summarised, as well as studies investigating the impact of physical parameters on their efficiency. It is concluded that this technology may be useful as a part of the measures used to lower urban air pollution levels, yielding ∼2% NOx removal in the immediate area around the surface, for optimised TiO<sub>2</sub>, in some cases, but is not capable of the reported high NOx removal efficiencies >20% in outdoor urban environments, and can in some cases lower air quality by releasing hazardous by-products. However, research into new material is ongoing. The reason for the mixed results in the studies reviewed, and massive range of removal efficiencies reported (from negligible and up to >80%) is mainly the large range of testing practices used. Before deployment in individual environments site-specific testing should be performed, and new standards for lab and field testing should be developed. The longevity of the materials and their potential for producing hazardous by-products should also be considered.https://www.mdpi.com/2073-4344/11/6/675photocatalysisNOxtitanium dioxideNO abatementconcreteair purification |
| spellingShingle | Hugo Savill Russell Louise Bøge Frederickson Ole Hertel Thomas Ellermann Steen Solvang Jensen A Review of Photocatalytic Materials for Urban NOx Remediation Catalysts photocatalysis NOx titanium dioxide NO abatement concrete air purification |
| title | A Review of Photocatalytic Materials for Urban NOx Remediation |
| title_full | A Review of Photocatalytic Materials for Urban NOx Remediation |
| title_fullStr | A Review of Photocatalytic Materials for Urban NOx Remediation |
| title_full_unstemmed | A Review of Photocatalytic Materials for Urban NOx Remediation |
| title_short | A Review of Photocatalytic Materials for Urban NOx Remediation |
| title_sort | review of photocatalytic materials for urban nox remediation |
| topic | photocatalysis NOx titanium dioxide NO abatement concrete air purification |
| url | https://www.mdpi.com/2073-4344/11/6/675 |
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