Quantitative photocatalyzed soot oxidation on titanium dioxide

Chin, Paul; Grant, Christine S.; Ollis, David F.

doi:10.1016/j.apcatb.2008.09.020

Cited by 24 publications

(9 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This inevitable heterogeneity of the thin soot layer due to the mortar texture was also reported in the literature (e.g. Chin et al, 2009;Simts et al, 2013). After 30 days of UVA irradiation, the diesel soot-stained mortar without TiO (SL0+UVA, Fig.…”

Section: Macro and Microscopic Observationssupporting

confidence: 66%

Assessing the effects of UVA photocatalysis on soot-coated TiO2-containing mortars

Rosa

Miller

Pozo-António

et al. 2017

Science of The Total Environment

View full text Add to dashboard Cite

The deposition of soot on building surfaces darkens their colour and leads to undesirable black crusts, which are one of the most serious problems on the conservation of built cultural heritage. As a preventive strategy, self-cleaning systems based on the use of titanium dioxide (TiO) coatings have been employed on building materials for degrading organic compounds deposited on building surfaces, improving their durability and performance. In this study, the self-cleaning effect of TiO-containing mortars coated with diesel soot has been appraised under laboratory conditions. The mortar samples were manufactured using lime putty and two different doses of TiO (2.5% and 5%). The lime mortars were then coated with diesel engine soot and irradiated with ultraviolet A (UVA) illumination for 30days. The photocatalytic efficiency was evaluated by visual inspection, field emission scanning electron microscopy (FESEM) and colour spectrophotometry. Changes in the chemical composition of the soot particles (including persistent organic pollutants) were assessed by analytical pyrolysis (Py-GC/MS) and solid state C NMR spectroscopy. The FESEM and colour spectrophotometry revealed that the soot-coated TiO-containing mortars promoted a self-cleaning effect after UVA irradiation. The combination of analytical pyrolysis and C solid state NMR showed that the UVA irradiation caused the cracking of polycyclic aromatic structures and n-alkyl compounds of the diesel soot and its transformation into methyl polymers. Our findings also revealed that the inclusion of TiO in the lime mortar formulations catalysed these transformations promoting the self-cleaning of the soot-stained mortars. The combined action of TiO and UVA irradiation is a promising proxy to clean lime mortars affected by soot deposition.

show abstract

Section: Macro and Microscopic Observationssupporting

confidence: 66%

Assessing the effects of UVA photocatalysis on soot-coated TiO2-containing mortars

Rosa

Miller

Pozo-António

et al. 2017

Science of The Total Environment

View full text Add to dashboard Cite

show abstract

“…Previous work by this group, and others [36][37][38][39], demonstrated that TiO2 is able to photocatalyse reaction (9), albeit very slowly and inefficiently (the photonic efficiency of this process was estimated as: 1.1x10 -4 [37]). In this initial study the metal film was photocatalytically deposited from a Pt ink which, instead of covering the whole TiO2 film, was drawn down the centre of a TiO2 film as a line, using the same conditions as used to make the Pt film illustrated in figure 1.…”

Section: + O2  Co2 (9)mentioning

confidence: 99%

Photodeposition of metals from inks and their application in photocatalysis

O’Rourke¹,

Wells²,

Mills³

2019

Catalysis Today

View full text Add to dashboard Cite

Films of Ag, Pt and Ag nanoparticles are photodeposited onto a range of commercial TiO2 based photocatalytic materials, such as paint, tile, awning fabric and glass, as well as a TiO2 sol-gel film, using an aqueous ink containing a sacrificial electron donor, glycerol, and the appropriate metal salt. The photodeposited metal films appear to be comprised of a fine covering of nanoparticular metal islands distributed evenly across the surface of the TiO2 sol-gel film, with some large aggregated particles for Pt (106 nm) and Au (33 nm). The rate of deposition of Ag is particularly fast, since a 10 s exposure to 2 mW cm-2 UVA light produces a very noticeable colour change, which is ca. 60 times that of the other two metal-ion containing inks. When combined with a photomask, the metal inks are used to create finely detailed metal film images on the surfaces of a wide variety of different, mainly commercial, photocatalytic materials; a fine metal mesh photomask is used to make metal micropatterns. When used to promote the photocatalysed oxidation of organic pollutants dissolved in aqueous solution, such as 4CP and MB, the enhancement in photocatalytic activity (compared to a plain TiO2 film) exhibited by a photodeposited Pt on TiO2 film is modest (16-35%), however, the enhancement is marked (234%) for the photocatalysed oxidation of CO to CO2. In contrast, the Au and Ag films appear to depress the inherent activity of the naked TiO2. The Pt/TiO2 film also enhances significantly the photocatalysed oxidation of a film of soot (179%) but not of stearic acid (-23%); the Ag and Au films appear to impede the former reaction. The Pt/TiO2 film exhibits the most significant enhancement in rate for the photocatalysed reduction of water to H2 by ethanol, i.e. 62 times that of the Ag/TiO2 film, which exhibits only a modest activity, which in turn is better than a naked TiO2 film which shows no activity. The potential of the metal (ion) inks to more easily make photodeposited metal films on semiconductor photocatalyst films is discussed briefly.

show abstract

“…The use of quartz crystal microbalances is particularly well suited to overcome these limitations by allowing to monitor the contaminant photo-induced mass changes and thus the ensuing selfcleaning effect. Several studies of the photocatalytic activity of thin films by quartz crystal microbalance (QCM) [25][26][27][28][29][30][31][32][33][34][35] or QCM-D [36][37][38][39] were conducted. They mainly dwell on TiO 2 deposited by sol-gel methods, 26,27,31,32,34 liquid routes, 30,33 atomic layer deposition (ALD), 37 or reactive magnetron sputtering.…”

Section: Introductionmentioning

confidence: 99%

“…Several studies of the photocatalytic activity of thin films by quartz crystal microbalance (QCM) [25][26][27][28][29][30][31][32][33][34][35] or QCM-D [36][37][38][39] were conducted. They mainly dwell on TiO 2 deposited by sol-gel methods, 26,27,31,32,34 liquid routes, 30,33 atomic layer deposition (ALD), 37 or reactive magnetron sputtering. 36,38 The reactions are studied in aqueous media [25][26][27][28][29][30][36][37][38][39] or in air with a contaminant either in the solid phase, 32 gas phase, 35 or deposited by the liquid route 31,33,34,37 with film thickness ranging from 60 nm to more than 1 μm.…”

Section: Introductionmentioning

confidence: 99%

Assessment of atomic layer deposited TiO2 photocatalytic self-cleaning by quartz crystal microbalance

Henry

Martins

Eustache

et al. 2020

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

The self-cleaning properties emerging from photocatalytic effects consist in the elimination of an organic contamination layer by light-induced redox reactions. Quartz crystal microbalances (QCMs), monitoring the contaminant mass loss under UV illumination, were used to investigate this effect and its efficiency. A new setup dedicated to such purpose is introduced along with the results of a self-cleaning experiment performed with a 20-nm TiO 2 thin film coated on a QCM by atomic layer deposition. In particular, a 10-nm paraffin oil thin film deposited under vacuum is shown to be degraded down to its complete removal according to a zeroth order photocatalytic reaction. Finally, the experimental opportunities offered by the new setup, such as a controlled environment composition, are presented.

show abstract

Quantitative photocatalyzed soot oxidation on titanium dioxide

Cited by 24 publications

References 43 publications

Assessing the effects of UVA photocatalysis on soot-coated TiO2-containing mortars

Assessing the effects of UVA photocatalysis on soot-coated TiO2-containing mortars

Photodeposition of metals from inks and their application in photocatalysis

Assessment of atomic layer deposited TiO2 photocatalytic self-cleaning by quartz crystal microbalance

Contact Info

Product

Resources

About