Ozone modification as an efficient strategy for promoting the photocatalytic effect of TiO2 for air purification

Article abstract of DOI:10.1039/c9cc00814d

We report a "two-bird-with-one-stone" strategy for photocatalytic air purification through the positive effect of ozone by surface modification over commercial TiO₂. The understanding of the photocatalytic degradation mechanism of volatile organic compounds is refreshed on the basis of in situ spectroscopic and theoretical studies.

Full text of DOI:10.1039/c9cc00814d

View Article Online
View Journal
ChemComm
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: F. Zhang, B. Hong,
W. Zhao, Y. Yang, J. Bao, G. Chen and S. Sun, Chem. Commun., 2019, DOI: 10.1039/C9CC00814D.
This is an Accepted Manuscript, which has been through the
Volume 52 Number
1 4 January 2016 Pages 1–216
Royal Society of Chemistry peer review process and has been
accepted for publication.
ChemComm
Accepted Manuscripts are published online shortly after
Chemical Communications
www.rsc.org/chemcomm
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1359-7345
COMMUNICATION
Marilyn M. Olmstead, Alan L. Balch, Josep M. Poblet, Luis Echegoyenet al.
Reactivity differences of Sc3N@C2n (2n 68 and 80). Synthesis of the
first methanofullerene derivatives of Sc N@D5h-C80
=
3
rsc.li/chemcomm

Please do not adjust margins
Page 1 of 5
ChemComm
View Article Online
DOI: 10.1039/C9CC00814D
COMMUNICATION
Ozone Modification as Efficient Strategy for Promoting the
Photocatalytic Effect of TiO2 for Air Purification
Fan Zhang,a,b,c Bin Hong,b Weisheng Zhao,*a,b Yue Yang,c Jun Bao,c Chen Gao*c and Song Sun*c,d
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
We report a “two-birds-with-one-stone” strategy for photocatalytic health and ecosystems.8 Even the so-called environmentally
air purification through the positive effect of ozone by surface friendly photocatalytic oxidation of VOCs is always
modification over the commercial TiO2. The understandings of accompanied by ozone generation when UV light with a
volatile organic compounds photocatalytic degradation mechanism wavelength of 185 nm is used as light source.9 These
is refreshed on the basis of in-situ spectroscopic and theoretical observations encourage us to address the issues of ozone and
study.
VOCs simultaneously. Although some studies have
demonstrated the oxidizability of gaseous ozone in the
9-10
photocatalytic process,2,
economizing ozone by surface
Volatile organic compounds (VOCs), which are usually emitted
from both biogenic and anthropogenic sources, is one kind of
the major air pollutants.1 Furthermore, they have been proven
to be crucial precursors of the formation of PM2.5 and
photochemical smog, which are also among the main pollutants
in the atmosphere.2 VOCs have different adverse effects on
human health,3 which makes the development of various
technologies for VOCs elimination urgent. Of these technologies
available, heterogeneous photocatalytic oxidation presents a
promising method because it is cost effective and
environmentally friendly.4 However, the surface active sites of
photocatalysts are not satisfied with the kinetic requirements,5
which is one of the challenges for the practical application of
photocatalytic air purification.
Ozone, as another gaseous pollutant, has also attracted
increasing attention in recent years.6 It is well known that ozone
naturally existing in the stratosphere plays an important role in
protecting human life and the environment.7 However, ozone in
the troposphere produced mostly by human activity is one of
the components of photochemical smog.8 With the increase of
automotive and industrial emissions, the tropospheric ozone
concentration has been increasing, which is harmful to human
modification over photocatalysts has never been studied, to the
best of our knowledge. Moreover, the underlying mechanism
between surface modification structure and photocatalytic
degradation route is subject to reveal.
In this work, we present a surface modification method to
obtain ozone-treated TiO2 for the photocatalytic degradation of
gaseous toluene, one of the typical VOCs. The positive effect of
ozone was also found in a prolonged reaction. The TiO2
(Degussa-P25-TiO2) has been chosen for investigation as it is the
most widely used photocatalyst.11 The hydroxyl groups on the
TiO2 surface play an important role in the photocatalytic
oxidation process: they serve as the most efficient adsorption
sites and participate directly in the photocatalytic oxidation. To
comprehensively elucidate the underlying mechanism, we
investigated the effect of ozone on the photocatalyst surface as
well as adsorption and photocatalytic degradation of gaseous
toluene by in-situ spectroscopic and theoretical studies. In-situ
diffuse reflectance infrared Fourier transform spectroscopy
(DRIFTS) measurements and theoretical calculations showed
that ozone affects the type and number of hydroxyl groups on
the TiO2 surface, making it more favorable for photocatalytic
degradation. Most importantly, ozone modification exerts a
promoting effect resulting in an excellent photocatalytic activity
and stability. The presented “killing two birds with one stone”
strategy can be an effective approach to promote the
photocatalytic effect of TiO2 for degradation of VOCs,
simultaneously making ozone profitable.
a. Fert Beijing Institute, BDBC, School of Microelectronics, Beihang University,
Beijing, 100191, China. E-mail: weisheng.zhao@buaa.edu.cn (W. Zhao)
b. Hefei Innovation Research Institute, Beihang University, Beijing 100191, China.
c. National Synchrotron Radiation Laboratory, Collaborative Innovation Center of
Chemistry for Energy Materials, University of Science & Technology of China,
Hefei, Anhui, 230029, China. E-mail: cgao@ustc.edu.cn (C. Gao),
suns@ustc.edu.cn (S. Sun)
TiO2 was modified in the ozone generator for 4 h to obtain O3-
modified TiO2 (O3-TiO2). The detailed experimental set up and
process are presented in Fig. S1 and have been partly reported
d. School of Chemistry and Chemical Engineering, Anhui University, Heifei, Anhui,
230601, China
† Electronic Supplementary Information (ESI) available: Experimental section, and
supporting figures. See DOI: 10.1039/x0xx00000x
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 2 of 5
COMMUNICATION
Journal Name
band at 3215 cm−1 and band at 1634 cm−1),15 isolated hydroxyl
View Article Online
groups (band at 3693 cm−1),13, 16 and bridging hydroxyl groups
DOI: 10.1039/C9CC00814D
(band at 3663 cm−1)13, 16 decreased, while the band of one type
of isolated hydroxyl groups (band at 3632 cm−1)13 increased
(detailed analysis of subtracted spectrum is shown in Fig. S4).
These results indicate that ozone modification changes hydroxyl
groups and Ti-OH2 on the TiO2 surface, which are generally
recognized as effective adsorption sites for VOCs, especially for
molecules containing the aromatic ring.17
Two distinguishable hydroxyl groups are bound to the TiO2
surface: one hydroxyl group bridges two surface vicinal Ti4+ ions,
and the other hydroxyl group is a terminal Ti-OH group.16
According to our theoretical calculations based on the
COMPASS force field,18 ozone tends to interact with bridging
hydroxyl groups rather than terminal hydroxyl groups (Fig. S5).
The bridging hydroxyl groups are more acidic than singly
coordinated hydroxyl groups.16 It is possible that the ozone
molecules show basic properties and tend to interact with acidic
surface OH groups. This is consistent with the reports that
ozone favors to form hydrogen bonds with acidic surface OH
groups via terminal oxygen atoms.19 The presence of ozone-
modified bridging hydroxyl groups (Fig. 3, Scheme I) is
confirmed by the appearance of a band resulting from the
perturbed OH groups at about 3566 cm−1. It is well known that
Ti4+ ions exposed on the TiO2 surface are Lewis acid sites.20
Therefore, ozone can also bind to Ti4+ ions via one of its terminal
atoms (Fig. 3, Scheme II). The decrease of the bands of adsorbed
water (Ti-OH2) indicates that ozone modification may also take
place on Ti-OH2 (Fig. 3, Scheme III). For TiO2, it is well accepted
that surface hydroxyl groups are derived from the dissociative
chemisorption of molecular water and serve as reactive sites.21
Further theoretical calculations (Fig. 3) showed that the water
molecules are easier to chemical dissociate adsorb on the TiO2
surface after ozone modification. This result is consistent with
the results of the X-ray photoelectron spectroscopy (XPS) (Fig.
S6 and Table S1) and DRIFTS measurements: after ozone
modification, the proportion of O in the form of surface
hydroxyl groups increased, and especially some new small
Fig. 1 (a) Degradation rates of TiO2 and O3-TiO2 for repeated photocatalytic
degradation of toluene under UV irradiation (λ > 300 nm). (b) The corresponding
mineralization rate of toluene (the calculation method is presented in Supporting
Information) over TiO2 and O3-TiO2 depending on the reaction run. The initial
toluene concentration was 500 ppmv and the relative humidity level was 80%.
in our previous study.12 Fig. 1(a) displays the photocatalytic
performances of the samples for toluene degradation in a
prolonged test with an initial toluene concentration of 500
ppmv. Self-photolysis, namely toluene degradation under
irradiation without photocatalyst, was also performed under
the same conditions (Fig. S2). Only about 2.9% toluene was self-
photolyzed after 1 h irradiation in such light source (Fig. S3). The
O3-TiO2 photocatalyst exhibited a much higher rate of toluene
degradation than TiO2, especially in the second to the sixth
consecutive reaction run. Fig. 1(b) shows the corresponding
mineralization rates of toluene on TiO2 and O3-TiO2 depending
on the reaction run. The mineralization rate of toluene on O3-
TiO2 increased about 20% in comparison to TiO2 after three
consecutive reaction runs, indicating that most of the toluene
was completely oxidized to CO2 on O3-TiO2. These results
indicate that O3 can not only promote the photocatalytic
degradation of toluene but also facilitate the complete
oxidation of toluene and organic intermediates whose further
oxidation is considered as the rate-determining step in the
whole degradation process.13 The promoting effect of ozone
sustained even after six runs, implying that O3-based species on
the TiO2 surface act against self-decomposition during the
reaction and that the stability of O3-TiO2 is satisfactory.
To elucidate the role of ozone in the photocatalytic degradation
of toluene, DRIFTS spectra of TiO2 and O3-TiO2 were collected
(Fig. 2). After ozone modification, some surface hydroxyl groups
formed on TiO2, as indicated by the appearance of small bands
in the 3900–3700 cm−1 range and the band at 3648 cm−1,
assigned to isolated hydroxyl groups.14 The new bands at 1580,
1298, and 1262 cm−1 might be related to the introduction of
ozone. Meanwhile, the bands of adsorbed water (Ti-OH2, broad
Fig. 3 Dissociation energies of water molecules (the calculation method is
presented in Supporting Information) on (a) TiO2 surface, and O3-TiO2 surface
when ozone interacts with (b) bridging hydroxyl groups, (c) Ti4+ ions, and (d) Ti-
OH2.
Fig. 2 DRIFTS spectra of TiO2 and O3-TiO2.
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 5
ChemComm
Please do not adjust margins
Journal Name
COMMUNICATION
hydroxyl bands appeared, and the intensity of the band at 3632
cm−1 increased. Ozone adsorbs dissociatively on the strong
Lewis acid sites on oxide surface resulting in the formation of
free oxygen molecules and oxygen atoms that remain attached
to the site.19 These oxygen atoms on strong Lewis acid sites can
react with water to generate surface-bound hydroxyl groups.22
Our results of the DRIFTS measurements and the theoretical
calculations are consistent with these findings. Regarding to the
decrease of the band at 3693 cm−1, it may be attributed to
weakly adsorbed hydroxyl groups, which desorb during ozone
modification.
View Article Online
DOI: 10.1039/C9CC00814D
Fig. 4 shows the DRIFTS spectra for the adsorption of toluene on
TiO2 and O3-TiO2 from 0 to 15 min (toluene adsorption reached
equilibrium) at room temperature, along with the spectra for
the samples irradiated under UV light after the adsorption
equilibrium. After adsorption of toluene, the intensity of the
characteristic bands of the surface hydroxyl groups decreased,
and the characteristic bands of toluene (3086, 3066, 3033, 2935,
2880, 1605, 1496, 1451, and 1380 cm−1) appeared,13 indicating
binding of toluene to hydroxyl groups. The interaction between
toluene and hydroxyl groups on the surfaces of TiO2 and O3-TiO2
produced new bands at 3577 and 3560 cm−1, respectively.13
Comparison of the spectra at 0 and 15 min (Fig. 4(b)) reveals a
blue shift of the band at 1262 cm−1 to 1265 cm−1 and a red shift
of the bands at 1580 and 1298 cm−1 to 1569 and 1296 cm−1,
respectively. In order to obtain the surface structure of O3-TiO2
corresponding to these bands, we theoretically calculated the
infrared spectra of ozone bound to the bridging hydroxyl groups,
Ti4+ ions, and Ti-OH2 as well as the infrared spectra when
toluene is introduced into these structures (Fig. S7). The
theoretical calculations and DRIFTS results showed that ozone
is supposed to bond surface hydroxyl groups, Ti-OH2, and Ti4+
ion sites, leading to the formation of the bands at 1580, 1298,
and 1262 cm−1, respectively. The adsorption of toluene on
surface hydroxyl groups and Ti-OH2 hinders the vibration of
ozone molecules (Fig. 3, Scheme I, III), resulting in a red shift of
the bands at 1580 and 1298 cm−1, respectively. The shift of the
band at 1262 cm−1 is probably due to binding of toluene to
ozone (Fig. 3, Scheme II). Our previous study has demonstrated
that the aromatic ring of toluene is electron deficient relative to
the methyl group.23 So it is easier to interact with electron-
donors. Due to the terminal oxygen atom of ozone molecule
provides an electron lone-pair, the adsorption of toluene via n-
π interactions increases the O=O vibration and the blue shift of
the characteristic band of ozone bound to Ti4+ sites. Comparison
of the characteristic band of adsorbed toluene in the subtracted
IR spectrum (Fig. S8) showed that the adsorption capacity of
toluene on TiO2 is slightly lower than that on O3-TiO2, which is
probably due to the large number of hydroxyl groups on the O3-
TiO2 surface, mainly with characteristic bands at 3648 and 3632
cm−1. Hydroxyl groups with these characteristic bands show a
stronger reactivity to adsorb toluene than other types of
hydroxyl groups.14 Furthermore, on the O3-TiO2 surface, toluene
molecules can also be adsorbed on ozone sites. It is worth
noting that no intermediate of toluene degradation appeared
during the adsorption process. It indicates that ozone did not
react with toluene directly before irradiation.
Fig. 4 In-situ DRIFTS spectra of toluene adsorption on (a) TiO2 and (b) O3- TiO2 from
0 to 15 min followed by UV irradiation for 20 min.
1644, 1582, 1520, 1416, 1308, and 1221 cm−1) appeared.17, 24
These findings indicate that toluene adsorbed on TiO2 and O3-
TiO2 were photocatalytic decomposed, and that benzoic acid
and benzaldehyde formed as intermediate products in the
process of photocatalytic degradation of toluene. This
observation agrees well with our previous investigation.12 The
red shift of the 3086 cm−1 band may be caused by the formation
of aldehyde and carboxyl groups from methyl groups on the
aromatic ring during the photocatalytic reaction. The intensity
of the infrared absorption in the range of 3500–3200 cm−1
caused by the vibration of surface hydroxyl groups and water
molecules decreased. This indicates that surface hydroxyl
groups and water molecules are consumed during the
photocatalytic degradation of toluene. In addition, in O3-TiO2,
the bands at 1569 and 1296 cm−1 disappeared, and the band at
1265 cm−1 red-shifted to 1262 cm−1 and decreased in intensity.
This can be explained by the participation of surface hydroxyl
groups and water molecules in the photocatalytic reactions,
resulting in disappearance of the bands at 1569 and 1296 cm−1.
The shift of the band at 1265 cm−1 may be due to the desorption
of toluene weakly adsorbed on ozone molecules under
irradiation. Importantly, some ozone molecules bound to Ti4+
ions were involved in the photocatalytic reaction and caused a
decrease of the 1262 cm−1 band.
Since the light source used in this study did not produce UV light
with wavelengths below 300 nm, ozone self-photolysis did not
occur in our experiment.25 Therefore, only TiO2 is active under
irradiation and absorbs photons with energies greater than its
band gap to generate electron–hole pairs.26 Ozone is
−
electrophilic and can accept electrons to form O3 species,
which are unstable intermediates that decompose to O2 and
O−.27 O2 reacts with photogenerated electrons to form
−
superoxide (O2 ·) radicals, which are the attacking radicals
toward toluene directly.28 As expected, the electron spin
−
resonance (ESR) results (Fig. S9(a)) suggest that O2 · radicals
were generated during the photocatalytic reaction on O3-TiO2
−
and TiO2, and that the amount of O2 · radicals generated on the
O3-TiO2 is larger than that on TiO2. Besides, O− can react further
with H2O to produce OH− and OH· radicals.29 OH· radicals are an
extremely reactive oxidant and can rapidly decompose
toluene.30 The amount of OH· radicals generated on the O3-TiO2
is approximately equal to that on TiO2 (Fig. S9(b)), implying that
After the adsorption of toluene reached equilibrium, UV
irradiation induced an evident decrease of the broad bands at
3577 and 3560 cm−1, a slight decrease of some characteristic
bands of adsorbed toluene, and a red shift of the band at 3086
cm−1. At the same time, some new bands attributed to (1685,
−
O2 · radicals are involved more in the degradation process. On
the other hand, ozone with interactions schemes as shown in
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 4 of 5
COMMUNICATION
Journal Name
Fig. 3 can capture photogenerated electrons, thus facilitating 3. L. Molhave, G. Clausen, B. Berglund, J. de Ceaurriz, A. Kettrup,
the separation of photogenerated carriers. All factors
mentioned above benefit the improvement of the
T. Lindvall, M. Maroni, A. C. Pickering, U. Risse, H.VRieowtAhrwticeleilOenrl,ine
B. Seifert and M. Younes, Indoor Air, 1997, 7, 225-240.
DOI: 10.1039/C9CC00814D
photocatalytic efficiency of TiO2. Although ozone is involved in 4. Y. C. Feng, L. Li, M. Ge, C. S. Guo, J. F. Wang and L. Liu, ACS
the photocatalytic reaction, only a small fraction is consumed, Appl. Mater. Inter., 2010, 2, 3134-3140.
as demonstrated by the prolonged test and the DRIFTS 5. A. Fujishima, X. T. Zhang and D. A. Tryk, Surf. Sci. Rep., 2008,
measurements (Fig. 4). This is possibly due to the generated 63, 515-582.
radicals being prone to attack toluene molecules according to 6. J. Patzsch and J. Z. Bloh, Catal. Today., 2018, 300, 2-11.
the preferential redox potential.26 Furthermore, the 7. M. Weber, M. Coldewey-Egbers, V. E. Fioletov, S. M. Frith, J. D.
modification method presented in this study may stabilize
ozone on the TiO2 surface. It should be pointed out that the O3-
Wild, J. P. Burrows, C. S. Long and D. Loyola, Atmos. Chem.
Phys., 2018, 18, 2097-2117.
TiO2 showed a better stability, which can be attributed to the 8. L. Zhong, C. S. Lee and F. Haghighat, Sustain. Cities. Soc., 2017,
rapid consumption of intermediates, such as benzaldehyde and 28, 466-472.
benzoic acid. These intermediates are the main reasons for the 9. H. Huang, H. Huang, Q. Feng, G. Liu, Y. Zhan, M. Wu, H. Lu, Y.
deactivation of TiO2, because they are strongly adsorbed on the
Shu and D. Y. C. Leung, Appl. Catal., B, 2017, 203, 870-878.
10. (a) F. Parrino, G. Camera-Roda, V. Loddo, V. Augugliaro and L.
Palmisano, Appl. Catal., B, 2015, 178, 37-43; (b) H. Huang, H.
Huang, L. Zhang, P. Hu, X. Ye and D. Y. C. Leung, Chem. Eng. J.,
2015, 259, 534-541.
surface of TiO2 and are difficult to be further oxidized.17
In summary, we report a “two-birds-with-one-stone” strategy
for air purification that surface modification of TiO2 with ozone
with specific schemes improve the photocatalytic performance
of TiO2 for toluene degradation. In-situ DRIFTS investigation and 11. J. Tripathy, K. Lee and P. Schmuki, Angew. Chem. Int. Ed., 2014,
theoretical calculations revealed that the interaction of ozone 53, 12605-12608.
with Ti4+ ions, Ti-OH2, and bridging hydroxyl groups result in the 12. F. Zhang, M. Wang, X. Zhu, B. Hong, W. Wang, Z. Qi, W. Xie, J.
number of surface hydroxyl groups for enhancement of toluene
adsorption capacity of TiO2. During the photocatalytic
Ding, J. Bao, S. Sun and C. Gao, Appl. Catal., B, 2015, 170-171,
215-224.
degradation, ozone derivatives can capture photogenerated 13. A. J. Maira, J. M. Coronado, V. Augugliaro, K. L. Yeung, J. C.
−
−
electrons to form O3 , O−, O2 · and OH· radicals after a series of
reactions. This process not only provides a large number of 14. H. X. Lin, J. L. Long, Q. Gu, W. X. Zhang, R. S. Ruan, Z. H. Li and
superoxide radicals with strong oxidizability but also promotes X. X. Wang, Phys. Chem. Chem. Phys., 2012, 14, 9468-9474.
the separation of photogenerated electron–hole pairs, thus 15. P. A. Connor, K. D. Dobson and A. J. McQuillan, Langmuir, 1999,
ultimately improving the mineralization efficiency of TiO2. Given 15, 2402-2408.
the increasingly serious pollution with VOCs and ozone, such a 16. M. D. Hernández-Alonso, S. García-Rodríguez, S. Suárez, R.
Conesa and J. Soria, J. Catal., 2001, 202, 413-420.
strategy can better eliminate VOCs pollution by exploiting
ozone through photocatalytic approach, which opens a new
way for the treatment of air pollution at the present stage.
This work was supported by the National Key Research and
Portela, B. Sánchez and J. M. Coronado, Catal. Today., 2013,
206, 32-39.
17. L. Cao, Z. Gao, S. L. Suib, T. N. Obee, S. O. Hay and J. D.
Freihauty, J. Catal., 2000, 196, 253-261.
Development Program of China (No. 2016YFB0700205), 18. A. Osnis, C. N. Sukenik and D. T. Major, J. Phys. Chem. C, 2011,
National Natural Science Foundation of China (U1632273, 116, 770-782.
U1832165), Foundation from Key Laboratory of Photovoltaic 19. K. M. Bulanin, J. C. Lavalley and A. A. Tsyganenko, Colloid.
and Energy Conservation, CAS (PECL2018KF012), Hefei Center Surface. A, 1995, 101, 153-158.
for Physical Science and Technology (2016FXZY002), Anhui 20. G. Martra, Appl. Catal., A, 2000, 200, 275-285.
Provincial Natural Science Foundation (17080885MB46), and 21. K. L. Yeung, S. T. Yau, A. J. Maira, J. M. Coronado, J. Soria and P.
the Beijing Advanced Innovation Center for Big Data and Brain
L. Yue, J. Catal., 2003, 219, 107-116.
Computing (BDBC). The authors thank the staffs from BL01B 22. R. Atkinson, Atmos. Environ., 2000, 34, 2063-2101.
beamline of National Synchrotron Radiation Laboratory (NSRL) 23. F. Zhang, X. D. Zhu, J. J. Ding, Z. M. Qi, M. J. Wang, S. Sun, J. Bao
at University of Science and Technology of China (USTC) and and C. Gao, Catal. Lett., 2014, 144, 995-1000.
BL01B beamline of National Center for Protein Science Shanghai 24. P. A. Deveau, F. Arsac, P. X. Thivel, C. Ferronato, F. Delpech, J.
(NCPSS) at Shanghai Synchrotron Radiation Facility, for
assistance during data collection.
M. Chovelon, P. Kaluzny and C. Monnet, J. Hazard. Mater.,
2007, 144, 692-697.
25. J. Xiao, Y. Xie, F. Nawaz, S. Jin, F. Duan, M. Li and H. Cao, Appl.
Catal., B, 2016, 181, 420-428.
26. P. Davit, G. Martra and S. Coluccia, J. Jpn. Petrol. Inst., 2004, 47,
359-376.
27. M. D. Hernández-Alonso, J. M. Coronsado, J. Soria, J. C. Conesa,
V. Loddo, M. Addamo and V. Augugliaro, Res. Chem. Intermed.,
2007, 33, 205-224.
28. M. Hayyan, M. A. Hashim and I. M. AlNashef, Chem. Rev., 2016,
116, 3029-3085.
29. K. Tanaka, K. Abe and T. Hisanaga, J. Photochem. Photobiol., A,
1996, 101, 85-87.
Conflicts of interest
There are no conflicts to declare.
Notes and references
1. X. Shen, Y. Zhao, Z. Chen and D. Huang, Atmos. Environ., 2013,
68, 297-314.
2. Y. Shu, J. Ji, Y. Xu, J. Deng, H. Huang, M. He, D. Y. C. Leung, M.
Wu, S. Liu, S. Liu, G. Liu, R. Xie, Q. Feng, Y. Zhan, R. Fang and X.
Ye, Appl. Catal., B, 2018, 220, 78-87.
30. R. Andreozzi, V. Caprio, A. Insola and R. Marotta, Catal. Today.,
1999, 53, 51-59.
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 5
ChemComm
View Article Online
DOI: 10.1039/C9CC00814D
Ozone Modification as Efficient Strategy for Promoting the
Photocatalytic Effect of TiO2 for Air Purification
Fan Zhang,a,b,c Bin Hong,b Weisheng Zhao,*a,b Yue Yang,c Jun Bao,c Chen Gao*c and Song Sun*c,d
A “two-birds-with-one-stone” strategy by ozone modification on TiO2 provides an approach
to address the gaseous pollution with ozone and VOCs.