NO-Reduction Performance Test for TiO 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), is one of the main sources of particulate matter. In this study, the reduction of NO using a coating material mixed with a titanium dioxide (TiO) photocatalyst was demonstrated. The NO reduction performance of the TiO 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 reduction can be achieved even if the NO gas concentration and UV-A irradiance are lower than those under the standard conditions when the TiO photocatalyst-infused coating was used. This study revealed that NO reduction can be realized through TiO 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 reduction performance of the TiO photocatalyst-infused coating. These findings can be used to evaluate a variety of construction materials with TiO photocatalysts in the future.