Abstract
The air pollution caused in urban areas by suspended particulate matter (SPM) and NO_x exhausted from cars has recently received much attention. Japanese Local governments, such as Tokyo and Osaka, are investigating the effectiveness of photocatalysts for decreasing NO_x concentrations. To improve indoor air quality in homes, in 1996 Daikin, Japan's largest air-conditioning manufacturer, developed and commercialized an air-purification system that uses photocatalysts to purify and sterilize air. We also designed and produced a trial air-purification system for removing NO_x.
