Photocatalytic Paving for NOx Abatement

摘要

In USA and many parts of the world, NO_x emissions have become a constraint for sustainable economic development due to ozone non-attainment. Under light illumination over a photocatalyst free radicals are generated to oxidize or decompose pollutants. In air pollution control, NOx are oxidized to nitric acid while volatile organic compounds (VOCs) are oxidized to water, CO2, and chloride. Ozone can be decomposed to oxygen over photocatalysts. Recent developments in Europe and Japan have demonstrated the interest in deploying photocatalytic technologies in environmental remediation. The photocatalytic coating has potential to economically reduce nitrogen oxides (NOx) emissions at ambient conditions nearly maintenance-free. We report the application of photocatalytic coating on concrete pavements to harvest the light energy for NOx pollution control. Further, photocatalysts can be enhanced with ferroelectric optical crystals (BaTiO3 & LiNbO3) via increased transmission/ scattering and electron-hole pair stabilization. The developed technology can help meet the tighter emission standards and will give architects and town planners a new weapon in the fight against air pollution in the foreseeable future.