Funabashi City Experiment: NOx Absorption by Paint? Potential of Photocatalytic Paints (2001)

Funabashi City Experiment: NOx Absorption by Paint? Potential of Photocatalytic Paints (2001)

In 2001, air pollution caused by automobile exhaust gas was considered a serious urban environmental issue in Japan. Nitrogen oxides (NOx) were one of the main causes, and the national and local governments were seeking various purification measures to prevent health hazards. The Funabashi City, Chiba Prefecture, experiment in NOx absorption using photocatalytic paint was an innovative approach born out of this trend. The paint used in the experiment contained titanium dioxide (TiO₂) and was characterized by its "photocatalytic" action, which oxidizes and decomposes NOx with the ultraviolet rays of sunlight. This is a "green" wall in the city. This was an attempt to redefine urban walls as "environmental devices," and it pointed the way toward a new urban policy that combines building materials and air purification technology. This case also influenced the subsequent introduction of green building materials and the concept of zero-emission buildings.