Supplementary material

Influence of domestic and environmental weathering in the self-cleaning

performance and durability of TiO2 photocatalytic coatings

Erika Iveth Cedillo-González, Virginia Barbieri, Paolo Falcaro, Leticia M. Torres-Martínez,

Isaías Juárez-Ramírez, Laura Villanova, Monica Montecchi, Luca Pasquali, Cristina Siligardi

S1. FEG-SEM and EDS analyses

To determine if EDS analysis could be used to give a quantitative estimation of the TiO 2

present in the as-prepared and detergent-treated mesoporous coatings, representative

micrographs and EDS spectra of these samples were performed. For the as-prepared sample,

the EDS spectra were taken from a zone of the sample that presented both the coating and the

Si substrate. The micrograph and EDS spectrum of the detergent-treated sample are also

report here (Figures 2e-f in the manuscript) for an easier comparison.

Figure 1Sa shows a zone of the as-prepared mesoporous sample where both the coating and

the Si substrate are visible. EDS spectra of Figures 1Sb-d of the same sample show that

titanium from TiO2 is present in the coating, although the Ti peak has a very low intensity

respect to that of Si from the substrate. The low intensity of the Ti peak was related with the

thickness of the as-prepared coating (117 nm). However, even in the zone 7 (Spectrum 7,

Figure 1Sc) of the sample where only the silicon substrate is visible, titanium was also

detected. These measurements confirmed that TiO2 is present in the as-prepared mesoporous

coating. On the other hand, in Figures 1Se-f the EDS analysis showed that titanium was not

present in the detergent-treated TiO2 mesoporous sample (centre of the sample). These results

confirm that TiO2 was removed from the substrate after treatment with detergent solution.

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Figure 1S: (a) FEG-SEM micrograph of the as-prepared mesoporous coating; (b-d) EDS

spectra of the Zones 6, 7 and 8 of the same sample, respectively; (e) FEG-SEM micrograph

and (f) EDS spectrum of the detergent-treated mesoporous coating (centre of the sample).

S2. FTIR analysis of the as-prepared and detergent-treated mesoporous coatings

Figure S2 shows the FTIR spectra in the 4000-2400 cm-1 range of the as-prepared and

isopropanol-treated mesoporous sample (before SA deposition). Both spectra were recorded

12h after the weathering treatment was completed. Two bands corresponding to the C-H

stretching modes of the aliphatic ends of the adsorbed IPA are visible in the isopropanol-

2

treated sample. This evidence was correlated with the non-reversible adsorption of

isopropanol on the surface of the coating, which remained attached to the sample after drying

at room temperature, preventing the interaction of SA with the TiO2 surface. As expected, the

as-prepared coating does not show any band in that range.

Figure S2. FTIR spectra of the as-prepared and isopropanol-treated mesoporous coatings.

S3. Permitted and hostile environments for several types of TiO2 coatings

Table S1 shows a general overview of the permitted and hostile environments for three types

of TiO2 coatings: dense, mesoporous and a TiO2 coating derived from a commercial nano-

dispersion (ø= 50 nm) [1S] (named "nanoparticled coating").

Table 1S. Permitted and hostile environments for nanoparticled, dense and mesoporous TiO2

coatings.

Type of TiO2 coatingPrincipal

characteristics

Permitted

environmentsHostile environments

Nanoparticled [1S]

Without porosity

Agglomerated

nanoparticles of 50 nm

Rain, acid rain and

domestic chemicals-

DenseWithout porosity

Particles of 41 nm

Rain, acid rain,

IsopropanolDetergent

Mesoporous

Mesoporosity

Particles of 21 nm

Pores of 17 nm

RainAcid rain, domestic

chemicals

References

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[1S] E.I. Cedillo-González, R. Riccò, M. Montorsi, M. Montorsi, P. Falcaro, C. Siligardi,

Self-cleaning glass prepared from a commercial TiO2 nano-dispersion and its photocatalytic

performance under common anthropogenic and atmospheric factors, Build. Environ. 71

(2014) 7–14.

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