Photocatalytic concrete pavements: Laboratory investigation of NO oxidation rate under varied environmental conditions

Sikkema, Joel K.; Ong, Sae-Kee; Alleman, James E.

doi:10.1016/j.conbuildmat.2015.10.005

Cited by 61 publications

(23 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 11 shows the effect of relative humidity on NOx degradation and nitrate selectivity. As previously reported [26,27,[40][41][42][43][44], the NO and NOx photonic efficiencies are reduced as relative humidity is increased, giving a reduction in nitrate selectivity. However, it is also noted that generated (NO 2 ) does not change significantly with relative humidity and the small drop may be driven by a reduction in NO oxidation as suggested above.…”

Section: The Influences Of Environmental Factorssupporting

confidence: 70%

Photocatalytic concrete for NOx abatement: Supported TiO2 efficiencies and impacts

Yang

Hakki

et al. 2019

Cement and Concrete Research

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: The Influences Of Environmental Factorssupporting

confidence: 70%

Photocatalytic concrete for NOx abatement: Supported TiO2 efficiencies and impacts

Yang

Hakki

et al. 2019

Cement and Concrete Research

View full text Add to dashboard Cite

show abstract

“…Concurrently, chemical reactions of molecules with the photoactivated states of the surface-active centers (S*) also lead to the return of the centers back to their ground state (S; Equation (16)).…”

Section: S + E − →mentioning

confidence: 99%

“…S* + R → S + P (16) In summary, there are two states of surface-active centers in heterogeneous photocatalysis: (i) the initial inactive ground state S; and (ii) the chemically active excited state(s) (S + , S − or S*). Both physical relaxation and chemical interactions of these excited state(s) with molecules return the centers back to their initial ground state.…”

Section: S + E − →mentioning

confidence: 99%

“…Several studies report on the performance of titania deposited on, or otherwise incorporated into cementitious substrates toward the minimization, if not suppression, of air pollutants (see, for example, Refs. [12][13][14][15][16][17][18]). Laboratory studies have shown, rather conclusively, that NO x can be oxidized to nitrate anions [19,20], while VOCs can be converted into CO 2 and H 2 O [21].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Heterogeneous Photocatalysis and Prospects of TiO2-Based Photocatalytic DeNOxing the Atmospheric Environment

Serpone

2018

Catalysts

View full text Add to dashboard Cite

This article reviews the efforts of the last two decades to deNOxify the atmospheric environment with TiO2-based photocatalytic materials supported on various cementitious-like substrates. Prior to undertaking this important aspect of applied photocatalysis with metal-oxide emiconductor photocatalysts, however, it is pertinent to describe and understand the fundamentals of Heterogeneous Photocatalysis. The many attempts done in a laboratory setting to degrade (deNOxify) the major components that make up the NOx, namely nitric oxide (NO) and nitrogen dioxide (NO2), but most importantly the efforts expended in deNOxifying the real environment upon depositing titania-based coatings on various model and authentic infrastructures, such as urban roads, highway noise barriers, tunnels, and building external walls among others, are examined. Both laboratory and outdoor experimentations have been performed toward NOx being oxidized to form nitrates (NO3−) that remain adsorbed on the TiO2-based photocatalytic surfaces (except in tunnels—indoor walls) but get subsequently dislodged by rain or by periodic washings of the infrastructures. However, no serious considerations have been given to the possible conversion of NOx via photocatalytic reduction back to N2 and O2 gases that would restore the atmospheric environment, as the adsorbed nitrates block the surface-active sites of the photocatalyst and when washed-off ultimately cause unduly damages to the environment.

show abstract

“…Recently, a lot has been done from the experimental perspective as well, see i.e. [3] for experimental studies on visible-light activated photo-catalytic asphalt, or [8,7,2,12] for photo-catalytic concrete products as well as [6] for actual observational studies. A comprehensive overview of the underlying principles in photo-catalysis processes in connection with removal of air pollutants is presented in [15,9,11] and the references therein.…”

Section: Introductionmentioning

confidence: 99%

Modelling, Simulation and Parameter Identification of Active Pollution Reduction With Photocatalytic Asphalt

et al. 2019

View full text Add to dashboard Cite

We develop and implement a numerical model to simulate the effect of photovoltaic asphalt on reducing the concentration of nitrogen monoxide (NO) due to the presence of heavy traffic in an urban environment. The contributions in this paper are threefold: we model and simulate the spread and breakdown of pollution in an urban environment, we provide a parameter estimation process that can be used to find missing parameters, and finally, we train and compare this simulation with different data sets. We analyze the results and provide an outlook on further research.

show abstract

Photocatalytic concrete pavements: Laboratory investigation of NO oxidation rate under varied environmental conditions

Cited by 61 publications

References 26 publications

Photocatalytic concrete for NOx abatement: Supported TiO2 efficiencies and impacts

Photocatalytic concrete for NOx abatement: Supported TiO2 efficiencies and impacts

Heterogeneous Photocatalysis and Prospects of TiO2-Based Photocatalytic DeNOxing the Atmospheric Environment

Modelling, Simulation and Parameter Identification of Active Pollution Reduction With Photocatalytic Asphalt

Contact Info

Product

Resources

About