Photocatalyst efficiencies in concrete technology: The effect of photocatalyst placement

Yang, Lu; Hakki, Amer; Wang, Fazhou; Macphee, Donald E.

doi:10.1016/j.apcatb.2017.10.013

Cited by 100 publications

(62 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1.71×10 -5 m 2 /s); Sc is the Schmidt number, calculated from the ratio of v/D, 0.883. Figure S1 in supplementary information) are still associated with the quartz sand support even after rigorous washing treatments (see the method of ref [25]) and agitation using ultrasound, demonstrating the robustness of the TiO 2 adhesion to the quartz surface and are reasonably well dispersed. The FT-IR spectra of pure quartz sand and TiO 2 modified quartz sand show a broad absorbance attributed to Ti-O-Si chemical linkages [28] (850 -1000 cm -1 ) suggesting a chemical bond between the support and TiO 2 particles ( Figure 4); this peak is better differentiated by the peak deconvolution superimposed on the spectra (Figure 4 Table 2 presents the binding performance of pure and TiO 2 modified quartz sand aggregate on mortar surfaces with 1/3 AED or 2/3 AED configurations (Figure 1).…”

Section: Photocatalytic De-nox Performancementioning

confidence: 94%

“…An alternative approach is to attach the TiO 2 photocatalysts to a surface-exposed support rather than incorporating them in the concrete [24], which can give a controllable dispersibility and exposure of TiO 2 photocatalysts on concrete surfaces. Considering the stability, large-scale and low cost applications, our recent study [25] has focussed on the application of photocatalyst to granular quartz supports, and mounting these on to the surface of concrete (see Figure 1). The loading properties and photocatalytic activity of quartz-mounted TiO 2 photocatalysts showed that TiO 2 can be stably bonded on the substrate surface, and yield significant improvements in NOx degradation compared with TiO 2 powder.…”

mentioning

confidence: 99%

“…Prior to FT-IR testing, samples were ground and passed through a 75μm sieve and the Perkin-Elmer Spectrum 2 spectrometer was calibrated for background corrections. Obtained FT-IR spectra were subjected to peak deconvolution analyses as in our previous study[25]. The deconvolution parameters were fixed for all samples and each deconvoluted peak was attributed according to literature assignations to specific bonded groups.Morphologies of samples were observed by scanning electron microscope (SEM, Zeiss EVO MA10) equipped with an energy dispersive X-ray spectrometry (EDAX, Oxford INCA) for elemental composition analyses.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Photocatalytic concrete for NOx abatement: Supported TiO2 efficiencies and impacts

Yang

Hakki

et al. 2019

Cement and Concrete Research

Self Cite

View full text Add to dashboard Cite

The potential of TiO2-based photocatalysts in mitigating the effects of environmental pollutants is evident in the scientific literature but the large-scale implementation of photocatalytic concretes still appears limited, despite the current global concerns over urban NOx pollution. Improvements in cost-effectiveness are required to enhance the case for a photocatalyst-modified infrastructure and this must address catalyst efficiency, catalyst loading and performance durability. This paper compares photocatalytic efficiencies of TiO2 supported on mortar surfaces with the more conventional TiO2 dispersed in mortar. The influences of environmental conditions, such as NO concentration and flow rate, UVA light intensity and relative humidity, on photocatalytic performance are also investigated using photonic efficiency as an indicator. The supported TiO2 shows greater degradation of NOx (De-NOx), at about 9 times higher than TiO2 powder dispersed in the mortar, ca. 150 times higher utilization efficiency, than that of TiO2 in traditional photocatalytic mortar (with 5% loading).

show abstract

Section: Photocatalytic De-nox Performancementioning

confidence: 94%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Photocatalytic concrete for NOx abatement: Supported TiO2 efficiencies and impacts

Yang

Hakki

et al. 2019

Cement and Concrete Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…Photocatalysts have been also applied on surfaces of building materials as active coatings (Nath et al 2013;Hot et al 2017;Yang et al 2018;Veltri et al 2019). Photocatalytic oxidation of dirt compounds by TiO 2 is widely known but its effectiveness is confined under UV radiation (Khan et al 2014;Khalid et al 2017).…”

Section: Introductionmentioning

confidence: 99%

Development of Multifunctional Coatings for Protecting Stones and Lime Mortars of the Architectural Heritage

Speziale

González-Sánchez

Taşcı

et al. 2020

International Journal of Architectural Heritage

View full text Add to dashboard Cite

Unique multifunctional coatings, comprising a 3D superhydrophobic agent and two nanostructured photocatalysts (solar-light sensitive 50/50 and 10/90 TiO 2 -ZnO nanoheterostructures), compatible with the inorganic substrates of the Built Heritage, have been designed.The synthesized nanoparticles showed an enhanced photocatalytic activity (tested by NO degradation) as compared with the raw TiO 2 and ZnO materials.Dispersing agents were used to optimize the coatings, avoiding agglomeration of the photocatalytic nanoparticles and increasing the stability of the suspensions. Four distinct dispersions were optimized and applied as coatings onto stony materials used in the Built Heritage, such as sandstone, lime mortar, granite and limestone. Their effectiveness was assessed by assessing hydrophobicity of the surfaces (static water contact angle), photocatalytic activity and self-cleaning as well as water vapour permeability of the treated specimens. These transparent coatings demonstrated high compatibility with the construction materials of the Architectural Heritage and showed a synergistic effect rendering a minimized water absorption, self-cleaning ability evidenced by the reduced adsorption of soiling deposits and a reasonable degradation of any trace that might be adsorbed, as well as a protecting hydrophobic environment for the photocatalyst.

show abstract

“…e incorporation of additions to modify and improve its fresh properties and its physical, mechanical, and durability properties, as well as to obtain new functional properties such as photocatalysis [1,2], antibacterial effects (Sikora et al [3,4]), hydrophobicity (Tittarelli [5] and Nunes and Slizkova [6]), and fungicide effects (De Muynck et al [7]) among others is currently an important research topic. In recent years, nanotechnology applied to cement-based materials has been growing since the use of additions of nanometric size significantly increases the effects on their mechanical and functional properties, and the combination of several additions might be very promising (Sikora et al [4], León et al [8], and Mohseni et al [9]).…”

Section: Introductionmentioning

confidence: 99%

Viability Study of a Safe Method for Health to Prepare Cement Pastes with Simultaneous Nanometric Functional Additions

Rubia

Lucas-Gil

Reyes

et al. 2018

Advances in Materials Science and Engineering

View full text Add to dashboard Cite

e use of a mixing method based on a novel dry dispersion procedure that enables a proper mixing of simultaneous nanometric functional additions while avoiding the health risks derived from the exposure to nanoparticles is reported and compared with a common manual mixing in this work. Such a dry dispersion method allows a greater workability by avoiding problems associated with the dispersion of the particles. e two mixing methods have been used to prepare Portland cement CEM I 52.5R pastes with additions of nano-ZnO with bactericide properties and micro-or nanopozzolanic SiO 2 . e hydration process performed by both mixing methods is compared in order to determine the efficiency of using the method. e hydration analysis of these cement pastes is carried out at different ages (from one to twenty-eight days) by means of differential thermal analysis and thermogravimetry (DTA-TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) analyses. Regardless of composition, all the mixtures of cement pastes obtained by the novel dispersion method showed a higher retardation of cement hydration at intermediate ages which did not occur at higher ages. In agreement with the resulting hydration behaviour, the use of this new dispersion method makes it possible to prepare homogeneous cement pastes with simultaneous functional nanoparticles which are physically supported on the larger particles of cement, avoiding exposure to the nanoparticles and therefore minimizing health risks. Manual mixing of cement-based materials with simultaneous nanometric functional nanoparticles on a large scale would make it difficult to obtain a homogenous material together with the health risks derived from the handling of nanoparticles.

show abstract

Photocatalyst efficiencies in concrete technology: The effect of photocatalyst placement

Cited by 100 publications

References 47 publications

Photocatalytic concrete for NOx abatement: Supported TiO2 efficiencies and impacts

Photocatalytic concrete for NOx abatement: Supported TiO2 efficiencies and impacts

Development of Multifunctional Coatings for Protecting Stones and Lime Mortars of the Architectural Heritage

Viability Study of a Safe Method for Health to Prepare Cement Pastes with Simultaneous Nanometric Functional Additions

Contact Info

Product

Resources

About