Evaluation of Photocatalytic Properties of Portland Cement Blended with Titanium Oxynitride (TiO2−xNy) Nanoparticles

Coatings

Juan D. Cohen¹  G. Sierra-Gallego²  Jorge I. Tobón¹ 

[1] Grupo del Cemento y Materiales de Construción CEMATCO, Universidad Nacional de Colombia, Facultad de Minas, 05001000 Medellín, Colombia; E-Mail:;Grupo Investigación en catálisis y nano materiales, Universidad Nacional de Colombia, Facultad de Minas, 05001000 Medellín, Colombia; E-Mail:

关键词: photocatalysis heterogeneous;    Portland cement;    self-cleaning;    nanoparticles of titanium oxynitride;    degradation of rhodamine B;    UV light;   

DOI  :  10.3390/coatings5030465

来源: mdpi

【 摘 要 】

Photocatalytic activity of Portland cement pastes blended with nanoparticles of titanium oxynitride (TiO_2−xN_y) was studied. Samples with different percentages of TiO_2−xN_y (0.0%, 0.5%, 1%, 3%) and TiO₂ (1%, 3%) were evaluated in order to study their self-cleaning properties. The presence of nitrogen in the tetragonal structure of TiO₂ was evidenced by X-ray diffraction (XRD) as a shift of the peaks in the 2θ axis. The samples were prepared with a water/cement ratio of 0.5 and a concentration of Rhodamine B of 0.5 g/L. After 65 h of curing time, the samples were irradiated with UV lamps to evaluate the reduction of the pigment. The color analysis was carried out using a Spectrometer UV/Vis measuring the coordinates CIE (Commission Internationale de l’Eclairage) L*, a*, b*, and with special attention to the reddish tones (Rhodamine B color) which correspond to a* values greater than zero. Additionally, samples with 0.5%, 1%, 3% of TiO_2−xN_y and 1%, 3% of TiO₂ were evaluated under visible light with the purpose of determining the Rhodamine B abatement to wavelengths greater than 400 nm. The results have shown a similar behavior for both additions under UV light irradiation, with 3% being the addition with the highest photocatalytic efficiency obtained. However, TiO_2−xN_y showed activity under irradiation with visible light, unlike TiO₂, which can only be activated under UV light.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.