Removal of NOx from air through cooperation of the TiO2 photocatalyst and urea on activated carbon fiber at room temperature

Removal of atmospheric NO to harmless N-2 was successfully achieved through the continuous oxidation and reduction of NO into N-2 using pitch-based activated carbon fiber (ACF), in which TiO2 and urea were co-supported. The combination of TiO2 and urea on the ACF gave high oxidation and reduction of NO. The TiO2 photocatalyst converted NO into NO2, which was immediately passed over urea on the ACF and reduced into harmless N-2. Humidity seemed to accelerate the desorption of NO2 from the TiO2 surface, but did not affect the NO oxidation, indicating that humidity did not interfere with the reaction of NO into N-2. The ACF system described is potentially very useful for the harmless removal of NO in the atmosphere near the roadside of urban area using natural wind effectively. (C) 2011 Elsevier B.V. All rights reserved.