In situ self-assembly of zirconium metal-organic frameworks onto ultrathin carbon nitride for enhanced visible light-driven conversion of CO2 to CO

Article abstract of DOI:10.1039/c9ta14005k

A series of Zr-porphyrin metal-organic framework (Zr-PMOF)/ultrathin g-C₃N₄ (UCN) (ZPUCN) heterostructure photocatalysts, as stable and efficient catalysts for the photoreduction of CO₂, have been fabricated via a facile in situ hydrothermal self-assembly method. An interfacial interaction is formed due to hollow Zr-PMOF nanotubes being surrounded by 3D ultrathin g-C₃N₄ (UCN) and benefiting from the ultrathin and conjugated π-structure of UCN, the unsaturated metal atoms and organic ligands of Zr-PMOFs can covalently link to organic g-C₃N₄. The interaction provides a platform for UCN as a conductor to transfer e^- or as a donor to transfer e^- to Zr-O cluster active sites to catalyze CO₂, substantially achieving the spatial separation of charge carriers and suppressing the photogenerated electron-hole (e^--h⁺) pair recombination rate. Benefitting from the cooperative effects of the well-designed nanostructure and chemical grafting, in the absence of triethanolamine, cocatalysts and photosensitizers, the optimized ZPUCN hybrid not only exhibits a better CO evolution yield (5.05 μmol g^-1 h^-1), which is 2.2 times and 3.2 times higher than those of pure Zr-PMOFs and UCN, respectively, but also displays excellent stability after 96 h photocatalysis. Information about the mechanism is also elucidated from selected characterizations.

Full text of DOI:10.1039/c9ta14005k

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In-situ self-assembly of Zirconium metal–organic
framework onto ultrathin carbon nitride for enhanced
visible-light-driven conversion of CO2 to CO
Yanan Wanga, Wenlong Zhenb, Yiqing Zenga, Shipeng Wana, Haiwei Guoa, Shule
Zhanga*, Qin Zhonga*
a School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
b School of Civil Engineering and Architectural, Anhui University of Technology, Maanshan, Anhui 243000, PR
China
* Corresponding author, Tel./fax: +86 25 84315517, E-mail: zq304@njust.edu.cn (Q. Zhong),
shulezhang@163.com (S.L. Zhang)
Abstract
A series of Zr-porphyrinic metal organic frameworks (Zr-PMOFs)/ultrathin g-
C3N4 (UCN) heterostructure photocatalysts (ZPUCN), as stable and efficient catalysts
for photoreduction CO2, are fabricated via a facile in situ hydrothermal self-assembly
method. The interface interaction is formed by hollow Zr-PMOFs nanotubes being
surrounded by 3D ultrathin g-C3N4 (UCN) and the covalent link due to the ultrathin and
conjugated π structure of UCN, unsaturated metal atoms and organic ligands of Zr-
PMOFs. The interaction provides a platform for UCN as a conductor to transfer e- or
donor to transferring e- to Zr-O cluster active sites to catalyze CO2, substantially
achieving the spatial separation of charge carries, suppressing the photogenerated
electron-hole (e--h+) pairs recombination rate. Benefitting from the cooperative effects
of well-designed nanostructure and chemical grafting, in the absence of triethanolamine,
cocatalysts and photosensitizers, the optimized ZPUCN hybrid not only exhibits a
better CO evolution yield (5.05 μmol∙g−1∙h−1), which is 2.2 times and 3.2 times higher
than that of pure Zr-PMOFs and UCN, but also display an excellent stability after 96 h
photocatalysis. Mechanism information is also elucidated from selected
characterizations.
Keywords: photocatalysis, CO2 reduction, heterojunction, Porphyrin metal organic
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frameworks, g-C3N4
1. Introduction
Greenhouse gases, carbon dioxide (CO2) levels have been increasing steadily over
the past century with the combustion fossil fuels and activities expansion of humankind
1-3. Along with the process of global industrialization, the global warming and the
limited fossil fuels are unavoidable problems that people have to face. One promising
and sustainable strategy to effectively and simultaneously solve these two
environmental pollution and energy crisis problems is a chemical conversion CO2 to
valuable chemical fuels through photo catalytic CO2 reduction by inexhaustible solar
4
energy . However, artificial photoreduction CO2 is still challenging due to the grand
kinetic and thermodynamic barrier of CO2 and the sluggish reaction kinetics for
producing solar fuels 2. The development of highly effective photocatalysts is a key to
boost the photoreduction process. Since the first investigation on TiO2 for CO2
photoreduction, lots of inorganic semiconductor photocatalysts have been explored and
7
studied. Most reductive inorganic semiconductors including TiO2 5, WO3 6, ZnO ,
8
Zn2GeO4 , are UV-light-responsive ones, which restricts the utilization of solar energy
for photocatalytic process.
Metal-organic frameworks (MOFs), as a new family of photocatalytic materials,
has exhibited outstanding catalytic performance due to their porous framework
structures, easy-manipulative functionalization, high designability and high surface
area 9. Extensive reports have studied that MOFs are excellent materials to photo-reduce
10
11
12, 13
CO2, such as UiO-based MOFs , MIL-based MOFs and PCN-based MOFs
.
Among them, Porphyrin metal organic frameworks (PMOFs), as a member of PCN-
based MOFs, are a kind of porous coordination materials with (metallo) porphyrin-
based linkers interconnected by metal ions or metal carboxylate cluster secondary
building units. (metallo) porphyrin and their derivatives are well known for working on
many biological functions, especially, light harvesting. Thus, some issues in
photocatalytic process (e.g., light harvesting) could be solved by using (metallo)
porphyrins as MOFs linkers 14-16. However, the photocatalytic efficiency of pure
2

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PMOFs is still unsatisfactory generally due to the fast combination of photoexcited
electron-hole (e--h+) pair, which is related to the energy-level alignment flaws and
asymmetry. Tremendous efforts have been devoted to boost the migration rate, such as
doping 17, tuning morphology 18, coupling with other semiconductors 1, 19. Among them,
constructing a heterojunction is one of the most effective strategy to address e--h+
recombination in the recent years 20. Especially, effective spatial separation of the
charge carriers can be achieved when two semiconductors have suitable energy levels,
consequently, suppressing the bulk and surface recombination 21. For instance, Zheng
synthesized 0D/2D carbon nitride quantum dots /porphyrin MOF for increasing
photocatalytic CO2 reduction, Ye et al. developed UiO-66/2D g-C3N4 nanosheet
heterostructures for CO2 photoreduction 22. Xiong et al designed g-C3N4
nanotubes/ZIF-8 composite to enhance CO2 conversion efficiency 23. However,
examples of PMOFs-based heterojunction photocatalysts for CO2 reduction are
insufficient. Graphitic carbon nitride (g-C3N4) have triggered great attentions in diverse
field due to its nontoxicity, high stability and cheap 24, 25. Notably, the suitable structure
(bandgap Eg=2.7 eV, energy potential of the conduction band ECB =−1.3 eV (versus
NHE) makes it an important player in the field of photocatalysis (CO2 photoreduction
and hydrogen generation) 23, 26. In addition, g-C3N4 with pliable framework can
effortlessly anchor or enclose on another materials, as a result, constructing the intimate
contacted interface 27. More importantly, as a metal free conjugated polymer
semiconductor, the purely organic nature of g-C3N4 plays a key strength to couple with
MOFs.
Herein, ultrathin 3D g-C3N4 was implemented to decorate hollow Zr-PMOFs
nanotubes to build a novel hybrid photocatalyst (ZPUCN-x, x is the actual mass of the
addition of UCN) under mild reaction conditions to cooperatively convert CO2
conversion. This work aims to make full use of the complementary features of Zr-
PMOFs and g-C3N4 to achieve the spatial separation of charge carries, suppressing the
photogenerated electron-hole (e--h+) pairs recombination rate. Benefitting from the
cooperative effects of well-designed nanostructure and chemical grafting, the optimized
ZPUCN heterojunctions boost charge transport and light-harvesting, and therefore
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presenting a high photocatalytic CO2 reduction efficiency. 3D ultrathin g-C3N4 (UCN)
exhibits superiority compared with the bulk g-C3N4 (BCN) fabricated by melamine.
Based on calculated energy band positions, the plausible enhanced mechanism for the
Zr-PMOFs/UCN composite was also proposed in detail.
2. Results and discussion
2.1. Structure and morphology
The XRD patterns of UCN, Zr-PMOFs and ZPUCN composites are shown in Fig.
1. The typical peak of UCN at 27.4 indexed to (002) plane is detected corresponding to
the typical stacked graphite-like structure (JCPDS No. 87-1526). For comparison, the
XRD pattern of bulk carbon nitride (BCN) was characterized. As shown in Figure 1a,
there are two typical peaks around at 13.1° (100) and 27.6° (002) for BCN. The negative
shift of (002) peak over UCN compared with that of the BCN is due to the loosely
layered structure 28. In addition, less prominent and broader typical peaks are relative
to the smaller length of interlayer periodicity, meaning UCN possess a smaller
interlayer periodicity and a larger layered spacing 29. SEM was carried to further make
the contrast of the pure BCN and UCN (Figure S3a and S3b). Unlike the tightly stacked
bulk BCN, UCN exhibits an ultrathin and loose stacked nanoflakes, which enhances
the specific surface area, and provides abundant active sites for anchoring other
materials and surface redox reactions. The consistent XRD pattern of Zr-PMOFs with
those reported previously 12 indicates Zr-PMOFs has been successfully synthesized. For
the ZPUCN-x composites, the in situ grafting of Zr-PMOFs on UCN has no obvious
effect on the crystal structure. The characteristic peaks of Zr-PMOFs are remained for
all ZPUCN hybrids, except for slight differences on the peak intensity, indicating that
more UCN has been introduced into the ZPUCN-x composites. The unique peaks of
UCN were not found obviously due to the relatively low peak intensity or/and low
content.
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Figure 1. XRD patterns of (a) Zr-PMOFs and ZPUCN-x, (b) UCN and BCN.
2.2. Photocatalytic activity
Photocatalytic CO2 reduction studies was implemented in a customized glass
system without any cocatalysts or electron donors under visible light. CO was detected
as the only gas product as shown in Figure 2a. Bare BCN or UCN is not active to reduce
CO2 under this system, the CO evolution rates are only 0.30 μmol h-1 g-1and 1.59 μmol
h-1 g-1 respectively. Besides, there are traces of CH4 (0.19 μmol h-1 g-1) in UCN (Figure
S4). The Zr-PMOFs showed moderate CO2 reduction with CO evolving rates of 2.32
μmol h-1 g-1. However, the ZPUCN-x heterojunctions photocatalysts show enhanced
CO2 photoreduction performance. Strikingly, ZPUCN-3 manifested higher CO2-to-CO
conversion rate of 5.05 μmol h-1 g-1 even in the absence of any sacrificial agent,
cocatalyst and photosensitizer, which is about 3.2 times and 2.2 times higher than that
of pure UCN and Zr-PMOFs. Meanwhile, ZPUCN-3 hybrids also present durable
photoreduction CO2 performance during consecutive photoreaction for 96 h (Figure S4),
providing an accumulated CO yield of ca. 4.89 × 102 μmol g-1. The remarkable CO2
reduction performance of ZPUCN-x should be related to the unique heterostructures
for accelerating the separation and transfer of photoinduced carriers. To exclude the
possibility that carbon source of CO is from acetonitrile or ZPUCN-x photocatalyst, a
blank experiment was carried out in the presence of N2 instead of CO2 under the same
other conditions, no CO product was detected, demonstrating that C species of CO
originates from CO2. The potential products generated in the liquid phase was detected
by another gas chromatography equipped by headspace sample injector and GC-MS.
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However, no HCHO, CH3OH and HCOOH were detected in the obtained liquid.
Generally, the products of the photoreduction of CO2 are HCOOH, CO, HCHO,
CH3OH, and CH4, the reduction potentials are -0.67 V, -.0.52 V, -0.49 V, -0.40 V and
-0.25 V, respectively 30. However, only CO is detected in the present work, indicating
good photocatalytic selectivity, which may be due to the following reasons. (i) The
photoreduction of CO2 tends to undergo proton-coupled electron transfer. But the
amount of H2O is too low to favor hydrogenation reaction under this experimental
condition. (ii) the reduction of CO2 to CO needs 2 protons, while 4, 6 and 8 electrons
are required to reduce it to HCHO, CH3OH, and CH4. (iii) Reduction potentials for the
formation of CO is moderate. In addition, the cyclic stability of CO evolution on
ZPUCN-3.0 hybrid structures was test. As shown in Figure S5, the CO yield has no
obvious decline after five photoreduction cycles. Furthermore, Figure S6 displays that
no obvious changes in the crystal structure could be observed in XRD patterns of fresh
and used ZPUCN-3.0.
Figure 2. (a) CO2 photoreduction activities of different samples. (b) Time-yield plots
of products.
The SEM images of pure UCN reveals the 3D ultrathin structure composed by the
cross-linked wrinkling or rolling nanoscale crystal layers (Figure 3a, b). Uniform Zr-
PMOFs prisms are prepared by a solvothermal reaction. Figure 3c shows the average
diameter and length of the Zr-PMOFs prisms are about 200 nm and 400 nm,
respectively. The magnified image presents the Zr-PMOFs are composed of well-
organized assembled ultrathin nanosheets (Figure 3d). By visualizing the morphology
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Figure 3. Typical SEM images of (a, b) UCN, (c, d) Zr-PMOFs and (e, f) ZPUCN-3
composites.
of the ZPUCN-3 composites (Figure 3e, f), Zr-PMOFs prisms are surrounded by
hierarchical UCN. No freestanding Zr-PMOFs prisms are observed, which indicates
that the growth of Zr-PMOFs prisms are exactly confined to the surface of UCN,
resulting in the formation of heterostructure interface. For comparison, the Zr-
PMOFs/BCN (ZPBCN) composite was prepared in a similar way expect that UCN was
used instead BCN shown in Figure S7. By contrast the SEM images, Zr-PMOFs are
evenly dispersed and are preferred to enclose on the surface of UCN because of the
loose lamellar structure, resulting to strong interaction between Zr-PMOFs and UCN.
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Overall, the SEM information verifies the formation of heterojunctions and suggests an
interfacial interaction between Zr-PMOFs and UCN. To further prove to the
observation interaction, XPS was measured as shown in Figure 4. The main elements
are C1s and N1s for pure UCN, and C1s, N1s, O1s, Zr3d for Zr-PMOFs (Figure 4a).
The XPS survey spectrum of ZPUCN-3.0 shows all of the above elements. With respect
to Zr 3d of Zr-PMOFs (Figure 4b), two characterized peaks at 184.75 eV and 182.43
eV were corresponded to Zr 3d3/2 and Zr 3d5/2, respectively, verifying the presence of
Zr4+ ions. By contrast, the Zr 3d binding energy of ZPUCN-3.0 had a negative shift to
184.45 eV and 182.14 eV, indicating the existence of interaction between UCN and Zr-
PMOFs.
Figure 4. (a) XPS survey spectra of UCN, Zr-PMOFs and ZPUCN-3.0, (b) High
resolution XPS spectra of Zr 3d of Zr-PMOFs and ZPUCN-3.0.
2.3. Optical and electronical properties
The UV-vis diffuse reflectance spectroscopy (DRS) was carried out to obtain the
optical information 31. To great extent. the electronic structure of g-C3N4 could be tuned
by the design of nanostructure. Accordingly, the adsorption edge of UCN has a
significant red shift from ~450nm (BCN) to ~650 nm, which mainly is due to nanoscale
effects 32. Furthermore, compared with BCN, the longer tail absorption from 550 nm to
800 nm is observed for UCN, which should be resulted from the abundant defects in
UCN. Zr-PMOFs can efficiently harvest visible light due to the H2TCPP ligand as a
visible light absorption unit shown in Figure 5. After UCN incorporation, a slight
reduction in the light harvesting capacity is observed for ZPUCN-x versus Zr-PMOFs,
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which should be related to the surface coating of UCN. However, importantly, it is
verified ultrathin porous layer could be integrated on Zr-PMOFs without weaken light
absorption ability by in-situ synthesis.
Figure 5. UV-vis diffuse reflectance for as-synthesized pure BCN, UCN, Zr-PMOFs
and ZPUCN-x.
Generally, the separation efficiency of photogenerated charge is a critical factor
affecting photocatalytic activities. Photoelectrochemical measurements were carried
out to further study the interface separation and migration properties of photoinduced
charge carriers. As shown in Figure 6a, the ZPUCN-x heterojunctions show enhanced
photocurrent intensity to different extent compared with pure UCN and Zr-PMOFs
during switching on visible light. The high photocurrent response of ZPUCN-x
heterojunctions should be owing to the lower recombination rate of the photoinduced
e--h+ pairs in the hybrid structures. Electrochemical impedance spectroscopy (EIS) is
also an efficient way to characterize the interfacial charge transfer, in which there is a
strong negative correlation between the radius of EIS curve and the charge transfer rate.
As presented in Figure 6b, the EIS Nyquist plots of the ZPUCN-x composites show
smaller radius than that of pure UCN and Zr-PMOFs. A smaller resistance leads to a
better conductivity and was favorable for the transmission of photogenerated electron.
Note that, the smallest radius from ZPUCN-3.0 hybrids is in accord with the result of
the photocurrent test and CO2 photoreduction performance. The current-time curve of
ZPUCN-3.0 composites is exhibited in Figure S8 under continuous light illumination.
The current density of ZPUCN-3.0 can remain unchanged after 3600s, suggesting a
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well photoelectrochemical stability of ZPUCN-3 in accord with the results of the
stability test of CO2 photoreduction.
Figure 6. (a) Transient photocurrent response, (b) the EIS Nyquist plots of the BCN,
UCN, Zr-PMOFs and ZPUCN-x.
In addition, the photoluminescence (PL) emission spectra was measured to further
investigate the lifetime of photogenerated charge carriers. As shown in Figure 7, the
photoluminescence of ZPUCN-3.0 quenched obviously compared with Zr-PMOFs,
indicating that the photoinduced charge recombination rate occurring in the hybrids has
been greatly inhibited 29, 33. The efficient charge migration should be ascribed to the
benefits of ZPUCN-3.0 heterojunction structure, since two-step excitation and charge
separation processes occur in the coupled system, in which the photogenerated e- and
h+ migrate to two materials in opposite directions and achieve e--h+ spatial separation
34. Hence, ZPUCN-3.0 enable provide long-lifetime e- for the CO2 photoreduction with
a higher performance than that of pure Zr-PMOFs. This result also shows good
agreement with the photoelectrochemical measurements discussed above.
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Figure 7. Photoluminescence spectra of Zr-PMOFs and ZPUCN-3.0.
2.4. Possible photocatalytic mechanism
A potential CO2 photocatalytic mechanism for the ZPUCN-x system was proposed
in Figure 8. The CO2 photoreduction test as the base of the mechanism information the
photogenerated charge transfer between the interfacial phase mainly follow the typical
heterojunction mechanism under visible light irradiation. Benefiting from the ultrathin
and conjugated π structure of UCN, unsaturated metal atoms and organic ligands of Zr-
PMOFs can be covalently linked to organic g-C3N4, leading an interfacial interaction.
The interfacial interaction provides a platform for UCN as a conductor to transfer e-
from ligands, or transferring e- to Zr-O cluster active sites to catalyze CO2. Since the
Zr-PMOFs are capable of the high CO2 uptake, subsequently, the enriched electrons
would interact with the enrichment of CO2 on Zr-PMOFs, facilitating the photocatalytic
efficiency. Moreover, more negative CB of UCN compared with Zr-PMOFs (Figure S9)
drives the transportation of e-. As a result, the electron re-localization suppressed the
recombination rates of photoexcited charge carriers in both UCN and Zr-PMOFs, which
is in accordance with photo-electrochemistry and PL results. In addition, as e- donators,
the photoinduced e- generated on the UCN would also react with CO2 directly.
Figure 8. Schematic illustration for the enhanced CO2 photoreduction
performance of the coupled of UCN and Zr-PMOFs under visible light irradiation.
Conclusions
It is demonstrated that a series of ZPUCN-x hybrid structure were synthesizes by
a facile in-situ solvothermal method, in which the Zr-PMOFs nanotubes are surrounded
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by 3D ultrathin g-C3N4. Benefiting from the ultrathin and conjugated π structure of
UCN, unsaturated metal atoms and organic ligands of Zr-PMOFs can be covalently
linked to organic g-C3N4. The interfacial interaction provides a platform for UCN
transferring e- to Zr-O cluster or as a conductor to transfer e-, thus the separation and
migration efficiency of photoexcited charge carriers on ZPUCN-x hybridization are
facilitated. In addition, mention that in the absence of triethanolamine, cocatalysts and
photosensitizers, the optimized ZPUCN-3.0 composites exhibit a CO2 to CO rate of
5.05 μmol∙g−1∙h−1, which is roughly 3.2 times and 2.2 times higher than that of the pure
UCN and Zr-PMOFs. Of importance is to note that the photocatalytic activity of
ZPUCN-3.0 composites has negligible decrease after 96 h photocatalysis, possessing
great prospect for implementing highly efficient solar fuel conversion.
Acknowledgements
This work was financially supported by the Key Project of Chinese National
Programs for Research and Development (2016YFC0203800), the National Natural
Science Foundation of China (51578288), Jiangsu Province Scientific and
Technological Achievements into a Special Fund Project (BA2016055 and
BA2017095), Jiangsu Province Scientific and Technological Project (BK20180449),
Top-notch Academic Programs Project of Jiangsu Higher Education Institutions, A
Project by the Priority Academic Program Development of Jiangsu Higher Education
Institutions
References
1.
Q. Mu, W. Zhu, X. Li, C. Zhang, Y. Su, Y. Lian, P. Qi, Z. Deng, D. Zhang and S. Wang, Applied
Catalysis B: Environmental, 2020, 262, 118144.
2.
3.
4.
X. Li, J. Yu, M. Jaroniec and X. Chen, Chem Rev, 2019, 119, 3962-4179.
R. Li, W. Zhang and K. Zhou, Adv Mater, 2018, 30, e1705512.
L. Hao, L. Kang, H. Huang, L. Ye, K. Han, S. Yang, H. Yu, M. Batmunkh, Y. Zhang and T.
Ma, Advanced Materials, 2019, 31, 1900546.
5.
6.
T. Inoue, A. FUJISHIMA, S. KONISHI and K. HONDA, Nature, 277, 637-638.
L. Yang, B. Liu, T. Liu, X. Ma, H. Li, S. Yin, T. Sato and Y. Wang, Advanced Materials, 2017,
7, 5075-5080.
7.
8.
9.
G. Mahmodi, Solar Energy Materials & Solar Cells, 2018, 111.
J. Wang, Y. Asakura and S. Yin, Nanoscale, 2019, 11, 20151-20160.
T. Zhang and W. Lin, Chemical Society Reviews, 2014, 43, 5982-5993.
12

Page 13 of 14
Journal of Materials Chemistry A
View Article Online
DOI: 10.1039/C9TA14005K
10.
11.
Z. Zheng, H. Xu, Z. Xu and J. Ge, Small, 2018, 14.
X. Li, Y. Pi, Q. Hou, H. Yu, Z. Li, Y. Li and J. Xiao, Chem Commun (Camb), 2018, 54, 1917-
1920.
12.
13.
14.
H. Q. Xu, J. Hu, D. Wang, Z. Li, Q. Zhang, Y. Luo, S. H. Yu and H. L. Jiang, J Am Chem Soc,
2015, 137, 13440-13443.
T. He, S. Chen, B. Ni, Y. Gong, Z. Wu, L. Song, L. Gu, W. Hu and X. Wang, Angew Chem Int
Ed Engl, 2018, 57, 3493-3498.
C. Monica, Wiederrecht, P. Gary, Mondloch, Joseph, Hupp, T. Joseph, Farha and K. Omar,
Chemical Communications, 2015, 46, 3501-3510.
15.
16.
W. Y. Gao, M. Chrzanowski and S. Ma, Chemical Society Reviews, 2014, 43, 5841-5866.
H. J. Son, S. Jin, S. Patwardhan, S. J. Wezenberg, N. C. Jeong, M. So, C. E. Wilmer, A. A.
Sarjeant, G. C. Schatz and R. Q. Snurr, Journal of the American Chemical Society, 2013, 135,
862-869.
17.
X.-S. Wang, C.-H. Chen, F. Ichihara, M. Oshikiri, J. Liang, L. Li, Y. Li, H. Song, S. Wang, T.
Zhang, Y.-B. Huang, R. Cao and J. Ye, Applied Catalysis B: Environmental, 2019, 253, 323-
330.
18.
19.
S. Wu, X. Xing, D. Wang, J. Zhang, J. Chu, C. Yu, Z. Wei, M. Hu, X. Zhang and Z. Li, ACS
Sustainable Chemistry & Engineering, 2019.
X. Deng, L. Yang, H. Huang, Y. Yang, S. Feng, M. Zeng, Q. Li and D. Xu, Small, 2019, 15,
1902287.
20.
21.
22.
K. Li, B. Peng and T. Peng, ACS Catalysis, 2016, 6, 7485-7527.
M. Marszewski, S. Cao, J. Yu and M. Jaroniec, Materials Horizons, 2015, 2, 261-278.
L. Shi, T. Wang, H. Zhang, K. Chang and J. Ye, Advanced Functional Materials, 2015, 25,
5360-5367.
23.
S. Liu, F. Chen, S. Li, X. Peng and Y. Xiong, Applied Catalysis B: Environmental, 2017, 211,
1-10.
24.
25.
S. Cao, J. Low, J. Yu and M. Jaroniec, Advanced Materials, 2015, 27, 2150-2176.
S. Zhang, P. Gu, R. Ma, C. Luo, T. Wen, G. Zhao, W. Cheng and X. Wang, Catalysis Today,
2019, 335, 65-77.
26.
27.
Y. Fang, Y. Xu, X. Li, Y. Ma and X. Wang, Angew Chem Int Ed Engl, 2018, 57, 9749-9753.
R. Wang, L. Gu, J. Zhou, X. Liu, F. Teng, C. Li, Y. Shen and Y. Yuan, Advanced Materials
Interfaces, 2015, 2, 1500037.
28.
Y. Li, F. Wei, Y. Liu, H. Zhao, X.-N. Ren, J. Liu, T. Hasan, L. Chen and B.-L. Su, Nanoscale,
2018, 10, 10.1039.C1037NR09660G.
29.
30.
31.
32.
J. Zhang, M. Zhang, C. Yang and X. Wang, Advanced Materials, 2014, 26, 4121-4126.
S. R. Lingampalli, M. M. Ayyub and C. N. R. Rao, ACS Omega, 2017, 2, 2740-2748.
C.-C. Wang, X.-H. Yi and P. Wang, Applied Catalysis B: Environmental, 2019.
M. Tahir, C. Cao, F. K. Butt, F. Idrees, N. Mahmood, Z. Ali, I. Aslam, M. Tanveer, M. Rizwan
and T. Mahmood, Journal of Materials Chemistry A, 2013, 1, 13949-13955.
J. Zhang, M. Zhang, R. Q. Sun and X. Wang, Angewandte Chemie International Edition, 2012,
51, 10145-10149.
33.
34.
S. N. Habisreutinger, L. Schmidt ‐ Mende and J. K. Stolarczyk, Angewandte Chemie
International Edition, 2013, 52, 7372-7408.
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DOI: 10.1039/C9TA14005K
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