Photocatalytic performance of TiO2 and WO3/TiO2 nanoparticles coated on urban green infrastructure materials in removing nitrogen oxide

• Published in: International journal of environmental science and technology (Tehran) 2018-03, Vol.15 (3), p.581-592
• Main Authors: Mendoza, J. A., Lee, D. H., Kim, L.-H., Kim, I. H., Kang, J.-H.
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Science and Engineering; Original Paper; Soil Science & Conservation; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 1735-1472; 1735-2630
• DOI: 10.1007/s13762-017-1425-9

This study investigated the performance of UV light active TiO 2 and UV–visible light active WO 3 /TiO 2 nanoparticles as air purifying materials that can be potentially applied to urban green infrastructures such as rain gardens and pervious pavements. Using a laboratory-scale continuous gas flow photoreactor, the removal efficiency of gaseous nitrogen oxide (NO x ) by two different photocatalytic nanoparticles coated on natural zeolites and pervious concrete blocks was evaluated. The results showed that the TiO 2 - and WO 3 /TiO 2 -coated zeolites are excellent photoactive materials providing enhanced air purification function (~95% removal efficiency of NO x ) under UV and UV–visible light irradiation, respectively. In contrast, both of the TiO 2 - and WO 3 /TiO 2 -coated pervious concrete blocks showed a measurable NO x removal (~60%) only under UV irradiation, whereas the visible light activity of the WO 3 /TiO 2 -coated concrete block was significantly reduced (~20%) mainly due to the decrease in the photocatalytic reaction sites for visible light. This study revealed the potential utility of photocatalytic nanoparticles in improving urban air quality, in the form of the surface component of various urban infrastructures.