NOx-Reduction Performance Test for TiO2 Paint.

In South Korea, the gradual increase in particulate matter generation has received significant attention from central and local governments. Exhaust gas, which contains nitrogen oxides (NO_x), is one of the main sources of particulate matter. In this study, the reduction of NO_x using a coating material mixed with a titanium dioxide (TiO₂) photocatalyst was demonstrated. The NO_x reduction performance of the TiO₂ photocatalyst-infused coating was evaluated by applying the ISO 22197-1: 2007 standard. Subsequently, the performance was evaluated by changing the NO gas concentration and ultraviolet (UV)-A irradiance under standard experimental conditions. It was determined that NO_x reduction can be achieved even if the NO gas concentration and UV-A irradiance are lower than those under the standard conditions when the TiO₂ photocatalyst-infused coating was used. This study revealed that NO_x reduction can be realized through TiO₂ photocatalyst-infused coating in winter or cloudy days with a low solar altitude. It was also confirmed that compared with the UV-A irradiance, the NO gas concentration has a greater effect on the NO_x reduction performance of the TiO₂ photocatalyst-infused coating. These findings can be used to evaluate a variety of construction materials with TiO₂ photocatalysts in the future. [ABSTRACT FROM AUTHOR]