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Juan D. Cohen
Grupo del Cemento y Materiales de Construción CEMATCO, Universidad Nacional de Colombia, Facultad de Minas, 05001000 Medellín, Colombia

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Journal article
Published: 17 October 2019 in Revista Facultad de Ingeniería Universidad de Antioquia
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Self-cleaning activity of Portland cement pastes blended with nanoparticles of titanium oxynitride (TiO2−xNy) was studied. Samples with various amounts of TiO2−xNy (1% and 3%) were evaluated under irradiation of UV and visible light, and with two curing ages (65 hour and 28 days). Rhodamine B was the pigment used and its loss of color on the cement pastes was carried out using a Spectrometer UV/Vis measuring the coordinates CIE (Commission Internationale de l’Eclairage) L∗, a∗, b∗. Discoloration of Rhodamine B on the surface of the samples was established as the photocatalytic efficiency coefficient (ε). In addition, samples with TiO2 nanoparticles (1% and 3%) were studied under the same conditions and their performances were compared with TiO2-xNy. The presence of nitrogen in the tetragonal structure of TiO2 was evidenced by X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectrophotometry and Carbon, Hydrogen and Nitrogen (CHN) analysis. The band gap for TiO2 and TiO2-xNy was determined by the transformed Kubelka-Munk function ( [F (R∞) hv]1/2). 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 in the early ages of curing time. TiO2−xNy showed activity under irradiation with visible light, unlike TiO2, which could only be activated under UV light. At the late curing ages, the samples with 3% of TiO2-xNy showed the highest efficiency under irradiation of UV and visible light.

ACS Style

Ludovic I. Dorkis; Juan David Cohen; Jorge I. Tobón. Photocatalytic activity under visible light irradiation of cement based materials containing TiO2-xNy nanoparticles. Revista Facultad de Ingeniería Universidad de Antioquia 2019, 87 -96.

AMA Style

Ludovic I. Dorkis, Juan David Cohen, Jorge I. Tobón. Photocatalytic activity under visible light irradiation of cement based materials containing TiO2-xNy nanoparticles. Revista Facultad de Ingeniería Universidad de Antioquia. 2019; (94):87-96.

Chicago/Turabian Style

Ludovic I. Dorkis; Juan David Cohen; Jorge I. Tobón. 2019. "Photocatalytic activity under visible light irradiation of cement based materials containing TiO2-xNy nanoparticles." Revista Facultad de Ingeniería Universidad de Antioquia , no. 94: 87-96.

Journal article
Published: 31 July 2015 in Coatings
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Photocatalytic activity of Portland cement pastes blended with nanoparticles of titanium oxynitride (TiO2−xNy) was studied. Samples with different percentages of TiO2−xNy (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 TiO2−xNy 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, TiO2−xNy showed activity under irradiation with visible light, unlike TiO2, which can only be activated under UV light.

ACS Style

Juan D. Cohen; Germán Alberto Sierra Gallego; Jorge I. Tobón. Evaluation of Photocatalytic Properties of Portland Cement Blended with Titanium Oxynitride (TiO2−xNy) Nanoparticles. Coatings 2015, 5, 465 -476.

AMA Style

Juan D. Cohen, Germán Alberto Sierra Gallego, Jorge I. Tobón. Evaluation of Photocatalytic Properties of Portland Cement Blended with Titanium Oxynitride (TiO2−xNy) Nanoparticles. Coatings. 2015; 5 (3):465-476.

Chicago/Turabian Style

Juan D. Cohen; Germán Alberto Sierra Gallego; Jorge I. Tobón. 2015. "Evaluation of Photocatalytic Properties of Portland Cement Blended with Titanium Oxynitride (TiO2−xNy) Nanoparticles." Coatings 5, no. 3: 465-476.