Kinetic Study of Photocatalytic Degradation of Nitrogen Monoxide with Titanium Dioxide Nanoparticles in Concrete Pavements

Abstract

Photocatalytic pavements are a promising solution for air pollution remediation from automobile sources; however, understanding their efficacy in real-world environments remains a challenge. This study proposed an environmental model based on reaction kinetics as a method to evaluate the significance of pollution reduction that could be expected from photocatalytic pavements. Thus, as the first step toward developing an environmental model, the objective of this study was to model the photocatalytic reaction kinetics of nitrogen monoxide (NO) reduction under different environmental conditions. To achieve this objective, photocatalytic concrete pavement samples were made with a two-layer concrete system. With the use of a plug flow photoreactor, laboratory experimental results showed that the photocatalytic oxidation of NO was reaction controlled and adequately described by the Langmuir–Hinshelwood model. The Langmuir–Hinshelwood constants were calculated for 25 unique environmental conditions by varying five levels of relative humidity and irradiance.