Photocatalytic activity of titanium dioxide nanoparticle coatings applied on autoclaved aerated concrete: Effect of weathering on coating physical characteristics and gaseous toluene removal

JOURNAL OF HAZARDOUS MATERIALS

卷:211

Article

Maury-Ramirez, Anibal²  Demeestere, Kristof¹  De Belie, Nele² 

[1] Univ Ghent, Res Grp EnVOC, Dept Sustainable Organ Chem & Technol, Fac Biosci Engn, B-9000 Ghent, Belgium

[2] Univ Ghent, Fac Engn & Architecture, Dept Struct Engn, Magnet Lab Concrete Res, B-9052 Ghent, Belgium

关键词: Titanium dioxide;    Coating;    Autoclaved aerated concrete;    Weathering;    Air purification;   

DOI  :  10.1016/j.jhazmat.2011.12.037

来源: Elsevier

【 摘 要 】

Autoclaved aerated concrete has been coated by TiO2 nanoparticles through a dip-coating (DC) and a novel vacuum saturation (VS) method to investigate the weathering resistance and gaseous toluene removal potential of both coating types. The effect of intensive weathering - corresponding to a period of about 25 years - on the coating characteristics was studied in terms of TiO2 content, coating thickness and color changes. Toluene removal was investigated in a lab-scale flow-through photoreactor at 24 degrees C and 52% relative humidity, and results obtained immediately after application of the coatings and after two weathering stages were compared. Weathering of the DC and VS coated samples resulted into a decrease of the coating layer thickness of more than 98%, confirmed by a decline in TiO2 content by more than 99% and 93%, respectively. Surprisingly, toluene removal efficiencies before and after weathering kept constant at about 95% for both coating types, corresponding to an elimination rate of 60-70 mg/(m(2) h) at an initial toluene concentration of 15 ppm(v) and a gas residence time of 3 min. Increasing the toluene load by applying higher toluene inlet concentrations (up to 35 ppm(v)) and lower gas residence times (1 min) did decrease the toluene removal efficiency to 32-41%, but elimination rates increased up to 214 mg/(m(2) h), being a factor of 1.6-4.5 times higher than reported in recent work. (c) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

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