Evaluation of Reducing NO and SO2 Concentration in Nano SiO2-TiO2 Photocatalytic Concrete Blocks

Abstract

The use of titanium dioxide in concrete block pavements is a promising approach to reduce air pollution in the roadside. When TiO2 is used as an additive of cement concrete or mortar, it is not dispersed uniformly due to agglomeration between particles causing the degradation of photocatalytic reaction. To improve the photocatalytic performance of TiO2, the Nano SiO2-TiO2 (NST) has been developed by coating TiO2 with SiO2 as a support using the sol-gel method. The environmental performance of concrete blocks incorporating NST as an additive was evaluated using both laboratory and full-scale chamber experiments. It was observed from laboratory environment chamber testing that the NO reduction efficiency of concrete blocks with 4% NST ranged from 16.5 to 59.1%, depending on the UV intensity. Results of the full-scale chamber test on NST concrete blocks indicated that the NO and SO2 reduction efficiencies were 22.3% and 14.4% at a 564W/m2 of solar radiation, respectively. It was found that the increase in UV intensity and solar radiation had a positive effect on decreasing NO and SO2 concentration. In the future, the NST will be applied at in-service photocatalytic block pavements to validate the environmental performance in field conditions.

Photocatalytic Activity and Mechanical Properties of Cement Slurries Containing Titanium Dioxide

“…Lee et al (2021) investigated the environmental photocatalytic performance of concrete blocks containing Nano SiO 2 -TiO 2 (NST) additive with SiO 2 acting as a coat and support for TiO 2 [25]. The small-scale and full-scale chamber laboratory tests showed reduced NO efficiency reaching a maximum of 59.1% depending on the UV intensity for concrete blocks containing 4% NST.…”

Evaluation Test of NO Degradation by Nano-TiO2 Coatings on Road Pavements under Natural Light

“…This distribution provides a feasible platformo-TiO 2 to degrade the vehicle exhaust. Nano-TiO 2 is a stable photocatalytic material to decompose vehicle emissions, and as a kind of self-cleaning material, the usage of Nano-TiO 2 on the pavement to reduce exhaust pollution has become one of the hottest fields in recent years [3][4][5][6][7][8][9][10][11][12][13]. Nano-TiO 2 particles can be used in many forms, such as mixing with pavement materials or spraying on pavement surfaces.…”