Preparation of Zn3In2S6/TiO2 for Enhanced CO2 Photocatalytic Reduction Activity Via Z-scheme Electron Transfer

Article abstract of DOI:10.1002/cctc.201801745

Photocatalytic reduction of CO₂ is increasingly attracting research interest for the growing concerns about climate change resulted from the greenhouse effect due to the industrial emission of CO₂. In this paper, we report the synthe

Full text of DOI:10.1002/cctc.201801745

Accepted Article
Title: Preparation of Zn3In2S6/TiO2 for enhanced CO2 photocatalytic
reduction activity via Z-scheme electron transfer
Authors: Houde She, Yan Wang, Hua Zhou, Yuan Li, Lei Wang,
Jingwei Huang, and Qizhao Wang
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: ChemCatChem 10.1002/cctc.201801745
Link to VoR: http://dx.doi.org/10.1002/cctc.201801745
A Journal of
www.chemcatchem.org

ChemCatChem
10.1002/cctc.201801745
FULL PAPER
Preparation of Zn In S /TiO for enhanced CO photocatalytic reduction
3
2 6
2
2
activity via Z-scheme electron transfer
Houde She,Yan Wang, Hua Zhou, Yuan Li, Lei Wang, Jingwei Huang, Qizhao Wang*
[
16]
Abstract: Photocatalytic reduction of CO
2
is increasingly attracting
and forming heterojunction with other semiconductors
research interest for the growing concerns about climate change
resulted from the greenhouse effect due to the industrial emission of
etc. have been explored to solve the problems. Amid them,
loading cocatalyst is an efficacious approach, which is
2 3 2 6 2
CO . In this paper, we report the synthesis of Zn In S modified TiO
capable of greatly improving the efficiency of photo-
nanocomposite via a facial hydrothermal method. The samples were
characterized by photoluminescence spectra (PL), UV–vis diffuse
reflectance spectra (DRS), X-ray diffraction (XRD), scanning
electron microscopy (SEM), transmission electron microscope (TEM),
X-ray photoelectron spectroscopy (XPS) and energy dispersive X-
[17]
generated carriers’ separation
.
Precious metals are often used as cocatalysts in carbon
dioxide reduction. Nevertheless, they are prohibited from
extensive use owning to their high cost. Accordingly, using
non-noble metals and its compound as cocatalysts have
ray spectroscopy (EDS). The production rate of CO from CO
dramatically improved over the obtained composite catalyst. The
contact between Zn In and TiO is responsible for this
2
is
[
18, 19]
[20]
been studied in a large scale
, such as copper oxide
and MoS . Among them, metal sulfides (CdS,
2 6
Zn In S , etc.) are visible-light-active
,
[
21]
[22]
Co
3
O
4
2
3
2
S
6
2
ZnIn
2
S
4
,
3
ameliorated photocatalytic activity because of the formation of the Z-
scheme charge transfer mechanism which favors the separation of
photo-induced charges.
photocatalysts with unique electronic structure and optical
[
23-28]
properties
.
Specifically, Zn-In-S,
a
visible light
responding ternary semiconductor, has drawn widespread
attention in photocatalysis owning to its high activity and
[
29, 30]
narrow bandgap
ZnIn shells as visible light sensitizers to improve light-
harvesting efficiency, and resultantly presents significantly
. For example, Bai’s group used
Introduction
2
S
4
With a considerable increase in greenhouse gas discharge
[
31]
enhanced photoelectrochemical performance
Yang et al. prepared ZnIn /TiO Z-system to reduce
recombination of photogenerated electrons and holes with
. Guang
[
1]
,
seeking an environment-friendly way to address the
problem generated by redundant carbon dioxide has
become an urgent need in today's society. Employing CO
2
S
4
2
2
[
32]
greatly ameliorated catalytic activity attained
cell ZnIn layers with rich zinc vacancies were
successfully designed by Xingchen Jiao et al. for acquiring
. One-unit-
as a reactant and chemically preparing expected materials
for industrial application is one of the most applicable ways.
2
S
4
2
So far, artificial conversion methods of CO mainly embrace
[
9]
higher efficiency in photocatalytic reduction of CO
many studies aiming at ZnIn , few are focused on
Zn In that plays the role of cocatalyst in photocatalytic
reduction of CO . In fact, Zn In owns suitable conduction
band position, which will incur a synergistic effect when
2
. While
[
2]
high-temperature catalytic hydrogenation , photocatalytic
S
4
[
3]
[4]
2
conversion , photoelectric cooperative catalysis , etc.
2 6
S
[
5-7]
[8-9]
3
Many catalysts like metal oxides
, sulfides
have been developed for the
purpose of reduction of CO driven by irradiation of visible
and
2 6
S
[
10-11]
2
3
nonmetallic oxide
2
[
33]
interacts with other semiconductor materials
regard, adopting Zn In as a cocatalyst can be a quite
promising strategy to enhance the photocatalytic activity of
TiO
In this study, a new hybrid photocatalyst, Zn
ZIS/TiO
. In this
light and exhibited excellent performance in catalyzing the
reaction.
3
2 6
S
Since S. Kato and F. Mosuo reported the oxidation of
2
.
tetralin while using TiO
phase under UV irradiation , TiO
studied because of its impressive chemical stability and low
cost. However, TiO shows egregious recombination of
2
as the photocatalyst in a liquid
In
2
S
6
/TiO
2
[
12]
3
2
has been extensively
(
2
), was synthesized by the solvothermal method.
The practical application of it shows that ZIS/TiO
composites have better photocatalytic properties than TiO
2
2
2
photogenerated charges and is exclusively responsive to
UV light, restricting its further pragmatic use. Therefore, a
alone. The reason presumably lies in that the contact
between cocatalyst Zn In and TiO forms a direct Z-
3
2
S
6
2
[
13-14]
[15]
list of strategies, such as doping
, loading cocatalyst
scheme electron transfer mechanism, raising the separation
efficiency of photo-generated carriers. The photocatalytic
reaction mechanism of Z-scheme electron transfer was
Dr. H. She, Y. Wang, H. Zhou, Y. Li, Dr. L. Wang, Dr. J. Huang, Prof. Q.
Wang
College of Chemistry and Chemical Engineering
Northwest Normal University
further
elucidated
by
fluorescence
spectroscopy,
and theoretical
transmission
calculations.
electron
microscopy
Lanzhou 730070, China
E-mail: wangqizhao@163.com; qizhaosjtu@gmail.com.
This article is protected by copyright. All rights reserved.

ChemCatChem
10.1002/cctc.201801745
FULL PAPER
Results and Discussion
because of its low content.
Morphological analysis of pure TiO
2
and 0.5ZIS/TiO
2
is
The structure of 0.5ZIS/TiO2 composite can be further
confirmed by EDS analysis as shown in Fig.3. The matching
elemental mappings of Ti are feckly uniform with that of O as
shown in Fig.3, both of which entirely shape through the TiO2
substrates structure. Additionally, it can be detected that the
equably distributed elemental mappings of Zn, In, S are similar
to each other, as suggested by its uniform colour, and no other
elements are detected at the same time, which validates the
coexistence of Zn In S and TiO .
performed using the field emission scanning electron
microscopy (FE-SEM) and the transmission electron microscope
(
TEM). Fig. 1a, b show illustrative images of the original TiO
and 0.5% Zn In sample. Compared with original P25,
.5ZIS/TiO has no obvious changes in particle size and
2
3
2 6
S
0
2
morphology. The possible reasons for this result could be
demonstrated as follows: The relatively low temperature was
used in the preparation of composite materials, which cannot
change the primeval physical properties. On the other hand, it
3
2
6
2
may be due to the low content of Zn
transmission electron microscope pictures of TiO
.5ZIS/TiO
3
In
2
S
6
on TiO
2
. The
and
2
0
2
are shown in Fig. 1c and 1d. Two sets of different
lattice images are observed in Fig. 1c. It can be seen that two
sets of the corresponding streaks, with a distance of 0.355 nm
and 0.226 nm, are in great keep with (101) lattice plane of
2 2
anatase TiO and (200) lattice plane of rutile TiO . There are two
sets of diverse lattice images in Fig. 1d. One set of the
corresponding fringes, with an interval of 0.351 nm and 0.193
nm, are in perfect accord with (101) lattice plane of anatase TiO
and (110) lattice plane of Zn In . The structure of 0.5ZIS/TiO
2
3
2 6
S
2
Fig.2 The X-ray diffraction patterns of TiO
a) and Zn In sample (b).
2 2
and ZIS/TiO samples
composite can be further confirmed by XRD and EDS analysis
(
3
2 6
S
(
(
shown in Fig. 2,3.) and selected area electron diffraction
shown in Fig. S2.).
Fig.3 Elemental mapping images of 0.5ZIS/TiO
2
In order to further study the valence state of Zn
composite material, XPS measurements were performed on the
as-prepared 0.5ZIS/TiO sample. In Fig. 4a, the Zn 2p core splits
into 2p 3/2 and 2p 1/2 peaks at 1021.70 eV and 1044.72 eV,
3 2 6
In S in the
2
Fig.1 SEM images of (a) TiO
and (d) 0.5ZIS/TiO
2 2 2
and (b) 0.5ZIS/TiO ; TEM images of (c) TiO
2
+ [34, 35]
2
.
which are consistent with the values for Zn
. Fig. 4b
The X-ray diffraction (XRD) patterns of the as-synthesized
pure TiO and TiO with different amounts of Zn In samples
are shown in Fig. 2a. The X-ray peaks of the TiO powder are in
shows the energy spectrum of In 3d, and there are two peaks
located at 444.8 eV and 452.4 eV, which correspond to the
binding energy of In 3d 5/2 and In 3d 3/2, respectively. It proved
2
2
3
2 6
S
2
[
36, 37]
fine accordance with rutile phase (JCPDS, No. 21-1276) and
anatase phase (JCPDS, No. 21-1272). The X-ray diffraction
that the valence state of element ln is +3
. The XPS
spectrum of S 2p in Fig. 4c can be divided into two peaks
observed at 161.4 eV and 162.8 eV, which belong to S 2p3/2
(
XRD) spectrum of the pure Zn
and it is found that the diffraction peak is finally consistent with
the JCPDS of the hexagonal phase Zn In , No. 80-0835.
Moreover, the diffraction peak intensity of ZIS/TiO gradually
decreases with the increase of the loading of Zn In in the
composites. The characteristic peak of Zn In is not observed
3 2 6
In S powder is shown in Fig. 2b,
[38, 39]
and S 2p1/2, indicating the valence of S is -2
Fig. 5a shows UV–vis diffuse reflectance spectra (DRS) of
the TiO , 0.3ZIS/TiO , 0.5ZIS/TiO , 0.7ZIS/TiO and Zn In . As
shown in Fig.5a, TiO possesses the strongest absorption in the
ultraviolet region, and the absorption wavelength is around 385
.
3
2 6
S
2
2
2
2
3
2 6
S
2
3
2
S
6
2
3
2 6
S
This article is protected by copyright. All rights reserved.

ChemCatChem
10.1002/cctc.201801745
FULL PAPER
nm. Fig. 5b shows that the band gap of pure TiO
2
is 3.22 eV,
. The strongest
lies in the visible light region as
shown in Fig.5a. The band gap of Zn In is 2.39 eV as shown
in the inserted digital photo of Fig.5b. Compared with pure TiO
the introduction of Zn In has few effects on the absorption of
TiO in the UV region. The absorption edge of ZIS/TiO exhibits
a valid redshift into the visible light region. The band gap of
ZIS/TiO is smaller than that of TiO , which is probably due to
the subsequently formed energy level after the contact of ZIS
and TiO as well as overlap and bending of the bands between
Zn In and TiO
photocatalytic
photoelectrochemical (PEC) properties of TiO
were measured. Fig. 5c shows the I-t curves of pureTiO
ZIS/TiO . ZIS/TiO presents ideal photocurrents intensity rather
than TiO . This trend is ascribed to the chummy interfacial links
between Zn In and TiO , which promote interfacial charge
transfer and enhance separation efficiency of photo-generated
reduction
catalyzed
by
ZIS/TiO
2
,
[
40, 41]
which agrees well with the reported value
absorption peak of Zn In
2
and ZIS/TiO
2
3
2
S
6
2
and
3
2
S
6
2
2
2
,
2
3
2
S
6
3
2
S
6
2
2
2
carriers. These photocurrent results suggest that Zn
3
In
2
S
6
can
and
2
2
efficaciously generate photo-induced electrons in ZIS/TiO
2
[
42]
effectively reduce the odds of recombination
also consistent with the test results of the CO
. This result is
2
photocatalytic
2
3
2
S
6
2
.
reduction performance under 300W Xe lamp. The
electrochemical impedance spectroscopy (EIS) can further
probe into the separation efficiency of photo-induced electron-
hole pairs and present the transfer resistance across the solid-
[
43, 44]
liquid junction in the electrode-electrolyte interface region
The Nyquist plots of TiO and 0.5ZIS/TiO are shown in Fig.5d.
At the same high frequency, TiO and 0.5ZIS/TiO show one arc
each while the arc of ZIS/TiO suddenly decreased at low
frequency, indicating Zn In /TiO possesses the greater
separation efficiency of electron-hole and the faster charge
.
2
2
2
2
2
3
2
S
6
2
[
9]
transfer on interface
.
2
Fig. 4 XPS spectra of (a) Zn 2p, (b) In 3d and (c) S 2p of 0.5ZIS/TiO .
Fig. 6 (a) PL spectra and (b) the N2 adsorption-desorption isotherm of
TiO2 and 0.5ZIS/TiO
2
.
Fig. 6a displays photoluminescence (PL) spectra of both
pure TiO and 0.5ZIS/TiO hybrid photocatalysts. Obviously, the
emission intensity of 0.5ZIS/TiO photocatalyst is higher than
that of pristine TiO . This phenomenon can be explained by the
2
2
2
2
presence of the more photoexcited charge carriers as well as
the reduced recombination rate in the photocatalytic system of
ZIS/TiO
2
in comparison to neat TiO
2
.
Commonly, the
fluorescence intensity of photocatalyst is lowered because
electrons are transferred to the surface of the cocatalyst which
suppresses the photocarriers’ recombination rate. However, in
this study, the fluorescence intensity of the composite material is
so apparently enhanced, which is not able to be appropriately
explained by the aforementioned theory. In this regard, it is
proposed that the composite material transfers electrons through
a Z-scheme electron transfer process, suggesting that in the
photocatalytic reaction, photogenerated electrons from
Fig.5 (a) UV–vis diffuses reflectance spectrum and (b) the optical absorption
edges of the TiO and ZIS/TiO samples; the inserted digital photo is the
optical absorption edges of Zn In (c) I-t curves of pure TiO and
.5ZIS/TiO photo-electrodes at 0.8 V vs. REH bias potential in 0.5 M Na SO
pH ∼ 7.35). (d) Nyquist plots of EIS measurements on the pure TiO and
.5ZIS/TiO at the open circuit potential in 0.5 M Na SO (pH ∼ 7.35).
conduction band (CB) of TiO
valence band (VB) of Zn In
between TiO and Zn In , and thus facilitated the valid charge
separation on both CB of Zn In and VB of TiO
To further understand the nano-porous structures of TiO
and 0.5ZIS/TiO , the N adsorption-desorption isotherm was
performed (Fig. 6b). The test results show that the specific
2
and photo-induced holes from
2
2
3
2 6
S recombined at the interface
3
2
S
6
.
2
2
3
2 6
S
0
2
2
4
3
2
S
6
2
.
(
2
2
0
2
2
4
2
2
In order to further understand the mechanism in CO
2
This article is protected by copyright. All rights reserved.

ChemCatChem
10.1002/cctc.201801745
FULL PAPER
2
-1
surface area of pure TiO
2
is 44.79 m ·g , whereas 0.5ZIS/TiO
2
photocatalytic CO
2
conversion of 0.5ZIS/TiO
2
under 300 W Xe lamps; (c) XRD
2
-1
has a higher specific surface area of 51 m ·g . A large specific
surface area is beneficial for a catalyst to provide more active
sites for the photocatalytic reaction. This result is consistent with
the photocatalytic performance test results.
patterns of 0.5ZIS/TiO sample before and after recycling.
2
To further investigate the fundamental mechanism of
photocatalytic CO conversion, the conduction and valence
band edge positions of Zn In and TiO are calculated
from the absolute electronegativity values via following
2
3
2
S
6
2
2
The consequences for CO photocatalytic conversion
[
45]
of the different samples are shown in Fig. 7a. It can be
clearly seen that the rates of photocatalytic reduction of
empirical formula
:
E
E
VB = X − E + 0.5 E
(2)
and X are valence band edge potential,
g
(1)
CO
for 0.3ZIS/TiO
μmol/(h·g) for 0.7ZIS/TiO
Also, their photocatalytic reduction rates of transforming
CO into CO are 0.15 μmol/(h·g), 12.93 μmol/(h·g), 23.35
2
into CH
4
are 0.2 μmol/(h·g) for TiO
, 6.19 μmol/(h·g) for 0.5ZIS/TiO
and 0.18 μmol/(h·g) for Zn
2
, 4.75 μmol/(h·g)
, 3.815
In
CB = EVB − E
g
2
2
E
VB, ECB, E, E
g
2
3
2
S
6
.
conduction band edge potential, the free electron energy on
hydrogen scale with energy of 4.5 eV, band gap and the
geometric mean of electronegativity of the constituent
atoms forming the semiconductor materials, respectively.
The electronegativity of the constituent atoms are XTi = 3.45,
2
μmol/(h·g), 8.73 μmol/(h·g) and 0.9 μmol/(h·g), respectively.
These results indicate that the photocatalytic reduction rate
of photocatalyst gradually rises along with the increment in
[
46]
X
O
= 7.54, XZn = 4.45, XIn = 3.1, and X
calculated electronegativity of TiO is 5.81 eV, and the
electronegativity of Zn In is 5 eV. The ECB and EVB of
TiO and Zn In are calculated by equations (1) and (2),
the valence band positions for TiO and Zn In are found
S
= 6.22
. The
the Zn
3
In
2
S
6
content. The composite material exhibits the
In was
2
best photocatalytic performance when 0.5% Zn
3
2
S
6
3
2 6
S
loaded on the composite. The absorption edge is
broadened and the charge separation efficiency is
2
3
2 6
S
2
3
2 6
S
enhanced at the interface between TiO
Z-scheme route, which is responsible for the high
photocatalytic activity of ZIS/TiO . Whereas, when Zn In
was loaded up to 0.7%, the photocatalytic activity
decreased. The CB electrons of TiO cannot be excited by
light when the redundant Zn In cover over TiO , leading
to less photo-generated electrons produced from TiO
consume the photo-generated holes of Zn In
2
and Zn
3
In
2
S
6
via a
to be at 2.92 eV and 1.7 eV, with their conduction band
positions at -0.3 eV and -0.69 eV.
2
3
2
S
6
The potentials for reducing CO
2
relative to the normal
hydrogen electrode in water are shown in equations 1 and 2
[
47]
2
(pH=7)
,
in which the protons come from the
3
2
S
6
2
photocatalytic water splitting.
+
−
0
2
to
It
CO
CO
2
2
+ 2H + 2e → CO + H
2
O, E redox = -0.53 eV (1)
+
−
0
3
2
S
6
.
+ 8H + 8e → CH
4
+ H
0
2
O, E redox = -0.24 eV (2)
+
+
eventually results in falling of charge carriers’ separation
efficiency and lower redox ability of photocatalyst. The
photocatalytic performance cycle test is shown in Fig.7b,
2H
2
O + 4h → 4H + O
2
, E redox = 0.82 eV
(3)
demonstrating
.5ZIS/TiO . The XRD results of the samples after cycling
further confirms its stability, as shown in Figure 7c.
a
stable recycling performance of
0
2
Fig.8 The CO
2
photocatalytic reduction error mechanism of ZIS/TiO
2
(a)
and the CO
2
photocatalytic reduction right mechanism of ZIS/TiO .
2
According to the suitable band gap structures and Fermi
[
48-51]
level
2 3 2 6
of TiO and Zn In S , the possible transfer
processes of photogenerated electron-hole pairs are
proposed in Fig. 8. One possible explanation of the photo-
generated carrier transfer process is presented in Fig. 8a.
The photogenerated electrons in the CB of Zn
to the CB of TiO while the photoexcited holes in the VB of
TiO transfer to the VB of Zn In . Subsequently, the ECB of
the photogenerated electrons is -0.3 eV. Because the E0
redox(CO /CO) is -0.53 eV, CO cannot be reduced to CO.
3 2 6
In S migrate
2
2
3
2 6
S
2
2
Thereby, the presumed process in Fig. 8a is not feasible in
this photocatalysis.
Another possible reaction mechanism is shown in Fig. 8b. In
the photocatalytic reaction, the solid-solid contact interface
Fig.7 (a) CO and CH
.7ZIS/TiO and Zn
4
generation velocity over TiO
2 2 2
, 0.3ZIS/TiO , 0.5ZIS/TiO ,
0
2
3
2 6
In S under 300 W Xe lamps; (b) Cycling runs in the
This article is protected by copyright. All rights reserved.

ChemCatChem
10.1002/cctc.201801745
FULL PAPER
between Zn
3 2 6 2
In S and TiO
serves as the combination center of Supporting Information Summary
the photogenerated electrons in the CB of TiO
2
and the
, resulting in an
The photogenerated electrons
involved in the reaction have a stronger reduction ability than
that of pure TiO , and thus perform a better photocatalytic
activity for CO
VB of TiO
[
40]
photogenerated holes in the VB of Zn
3
In
2
S
6
All the information about the testing methods of materials is
presented in the Supporting Information.
[
42]
increased fluorescence
.
2
[
32]
reduction . The photogenerated holes in the Acknowledgements
2
+
2
oxidize water to form H and O
2
, while the
simultaneously
. In summary, all of the
above analyses show that the electron transfer process of
ZIS/TiO is identified as Z-scheme electron transfer in this study.
This work is financially supported by the National Natural
Science Foundation of China (21663027, 21808189), the
Program for the Young Innovative Talents of Longyuan and the
Program for Innovative Research Team (NWNU-LKQN-15-2).
photogenerated electrons in the CB of Zn
reduce CO to generate CO or CH
3 2 6
In S
2
4
2
Keywords:
Conclusions
2 2 3 2 6
Cocatalyst, CO photocatalytic reduction, TiO , Zn In S , Z-
In summary, Zn
3
In
2
S
6
/TiO
2
as a new hybrid photocatalyst was
simple hydrothermal method.
was found to exhibit best photocatalytic activity
and excellent stability in CO reduction under simulated solar
scheme electron transfer
successfully prepared by
.5%ZIS/TiO
a
1
L. Wang, S. Duan, P. Jin, H. She, J. Huang, Z. Lei, T. Zhang and Q.
Wang, Appl. Catal., B, 2018, 239, 599-608.
0
2
2
2
3
C. S. Chen, W. H. Cheng, S. S. Lin, Appl. Catal., A, 2003, 238, 55-67.
light irradiation. The most likely reaction mechanism is the Z-
scheme electron transfer in this study, which was demonstrated
by the photoluminescence (PL) measurements and the results of
S. Sato, T. Morikawa, T. Kajino, and O. Ishitani, Angew. Chem., 2013
125, 1022-1026.
,
4
5
6
7
8
X. Chang, T. Wang, P. Zhang, Y. Wei, J. Zhao, and J. Gong, Angew.
Chem., 2016, 128, 8986 -8991.
the photocatalytic CO
Zn In can match with TiO
route for improving CO photocatalytic reduction efficiency. The
ZIS/TiO composites have strong photocatalytic activity
because of the higher electron-hole separation efficiency and
2
reduction. The band gap edge of
T. N. Huan, P. Simon, A. Benayad, L. Guetaz, V. Artero, and M.
Fontecave, Chem. Eur. J., 2016, 22, 14029-14035.
M. Karamad, H. A. Hansen, J. Rossmeisl, and J. K. Nørskov, ACS
Catal., 2015, 5, 4075-4081.
3
2
S
6
2
well, which provides a promising
2
2
a
Y. Pan, Y. You, S. Xin, Y. Li, G. Fu, Z. Cui, Y. Men, F. Cao, S. Yu, and
J. B. Goodenough, J. Am. Chem. Soc., 2017, 139, 4123−4129.
A. Aljabour, D. Hazar Apaydin, H. Coskun, F. Ozel, M. Ersoz, P.
Stadler, N. S. Sariciftci, and M. Kus, ACS Appl. Mater. Interfaces,
2
the stronger reduction ability than TiO .
2
016, 8, 31695-31701.
Experimental Section
9
1
X. Jiao, Z. Chen, X. Li, Y. Sun, S. Gao, W. Yan,C. Wang, Q. Zhang, Y.
Lin, Y. Luo, and Y.Xie, J. Am. Chem. Soc., 2017, 139, 7586−759.
J. Jin, J. Yu, D. Guo, C. Cui, and W. Ho, Small, 2015, 11, 5262-
0
Certain amount of (0.3%, 0.5%, 0.7%) Zn(NO
3 2 2
) ·6H O and
5
271.
In(NO ·4.5H O were dissolved in 54 ml ethylene glycol under
3
)
3
2
1
1
1
1
2
3
J. Low, J.Yu, and W. Ho, J. Phys. Chem. Lett., 2015, 6, 4244-4251.
K. Kato, F. Masuo, Kogyo Kagaku Zashi, 1964, 67(8), 1136–1140.
H. She, H. Zhou, L. Li, L. Wang, J. Huang and Q. Wang. ACS Sustain.
Chem. Eng, 2018, 6, 11939-11948.
constant magnetic stirring to form a solution, to which 0.3 g P25
was added and magnetically stirred for 0.5 h, followed by 1 h
ultrasonic oscillation to obtain a suspension, to which certain
amount of thioacetamide was added under magnetic stirring for
1
1
1
1
1
1
2
2
2
2
4
5
6
7
8
9
Z. Xiong, Z. Lei, S. Ma, X. Chen, B. Gong, Y. Zhao, J. Zhang, C.
Zheng, J. C.S. Wu, Appl. Catal., B, 2017, 219, 412–424.
L. L. Tan, W. J. Ong, S. P. Chai, A. R. Mohamed, Appl. Catal., B, 2015
0
.5 h. The mixed solution was poured into a 100 mL Teflon
vessel held in a stainless steel autoclave and was maintained at
40 °C for 12 h. After that, the system was cooled down to room
,
1
66-167, 251-259.
1
C. Wang, R. L. Thompson, J. Baltrus, and C. Matranga, J. Phys.
Chem. Lett., 2010, 1, 48-53.
temperature. The obtained yellow suspension was washed by
water and ethanol several times, and then completely dried in an
oven at 60 °C for 24 h. The molar ratio of Zn, In and
thioacetamide was kept at 1: 2: 8, and the molar ratio of Zn and
Z. Xiong, Z. Lei, C. C. Kuang, X. Chen, B. Gong, Y. Zhao, J. Zhang, C.
Zheng, J. C.S. Wu, Appl. Catal., B , 2017, 202, 695-703.
Q. Wang, T. Niu, L. Wang, C. Yan, J. Huang, J. He, H. She, B. Su and
Y. Bi, Chem. Eng. J, 2018, 337, 506-514.
2
TiO was 0.3%, 0.5%, 0.7% for different samples which were
Q. Wang, J. He, Y. Shi, S. Zhang, T. Niu, H. She, Y. Bi and Z. Lei,
Appl. Catal. B, 2017, 214, 158-167.
labeled as 0.3ZIS/TiO
respectively.
2
,
0.5ZIS/TiO
2
,
2
and 0.7ZIS/TiO ,
0 L. Tan, Y. Yang, N. Li, S. Chen, Z. Liu, Catal. Sci. Technol, 2017, 7,
315-1323.
1
0
.5 mmol Zn(NO
were dissolved in 54 ml ethylene glycol under constant
magnetic stirring for 0.5 h. Subsequently, mmol
3 2 2 3 3 2
) ·6H O and 1 mmol In(NO ) ·4.5H O
1
D. S. Lee, H. J. Chen, Y. W. Chen, J. Phys. Chem. Solids, 2012, 73,
6
61-669.
4
2
W. Tu, Y. Li, L. Kuai, Y. Zhou, Q. Xu, H. Li, X. Wang, M. Xiao and
thioacetamide was added to above solution under constant
magnetic stirring for 0.5 h. The following steps are the same
Z. Zou, Nanoscale, 2017, 9, 9065-9070.
3 R. Wei, Z. Huang, G. Gu, Z. Wang, L. Zeng, Y. Chen, Z. Liu, Appl.
Catal. B Environ, 2018, 231, 101-107.
as the synthesis of Zn
3 2 6 2
In S /TiO except that no P25 was
added during the experiment.
This article is protected by copyright. All rights reserved.

ChemCatChem
10.1002/cctc.201801745
FULL PAPER
2
2
2
4
K. Iwashina, A. Iwase, Y. H. Ng, R. Amal, A. Kudo, J. Am. Chem. Soc.,
015, 137, 604-607.
38 Zhang C, Xu Y J. ACS Appl. Mater. Interfaces, 2013, 5(24), 13353-
13363.
2
5 J. Han, Z. Liu, K. Guo, B. Wang, X. Zhang, T. Hong. Applied Catalysis
B: Environmental, 2015, 163: 179-188.
39 H. Yu, W. Liu, X. Wang, F. Wang, Appl. Catal. B-Environ, 2018, 225,
415-423.
6
W. Chen, Y. X. Hua, Y. Wang, T. Huang, T. Y. Liu, X. H. Liu, J. Catal.,
40 J. Pascual, J. Camassel, and H. Mathieu, Phys. Rev. Lett., 1977, 39,
2
017, 349, 8.
1490-1493.
2
2
7
8
S. K. Batabyal, S. E. Lu, J.J. Vittal, Cryst. Growth Des. 2016, 16, 2231.
A. Iwase, S. Yoshino, T. Takayama, Y. H. Ng, R. Amal, A. Kudo, J.
Am. Chem. Soc., 2016, 138, 10260.
41 H. Yu, P. Xiao, J. Tian, F. Wang, J. Yu, ACS Appl. Mater. Interfaces,
2016, 8, 29470-29477.
42 R. Ye, H. Fang, Y. Zheng, N. Li, Y. Wang, and X. Tao, ACS Appl.
Mater. Interfaces, 2016, 8, 13879-13889.
2
3
3
3
3
3
3
3
3
9
0
1
2
3
4
J. Song, C. Ma, W. Zhang, S. Yang, S. Wang, L. Lv, L. Zhu, R. Xia, X.
Xu, J. Mater. Chem. B, 2016, 4, 7909-7918.
43 N. Li, G. Liu, C. Zhen, F. Li, L. Zhang, H. Cheng, Adv. Funct. Mater.,
2011, 21, 1717-1722.
B. Xu, P. He, H. Liu, P. Wang, G. Zhou, and X. Wang, Angew. Chem.,
2
014, 126, 2371-2375.
Z. Bai, X. Yan, Z. Kang, Y. Hu, X. Zhang, Y. Zhang, Nano Energy ,
015, 14, 392-400.
44 Z. Hosseini, N. Taghavinia, N. Sharifi, M. Chavoshi, M. Rahman, J.
Phys.Chem. C, 2008, 112, 18686–18689.
2
45 Y. Xu and M.A.A. Schoonen , Am. Mineral., 2000, 85, 543-556.
46 D. C. Ghosh, T. Chakraborty, J. Mol. Struct. Theochem, 2009, 906,
87-93.
G. Yang, D. Chen, H. Ding, J. Feng, J. Z. Zhang, Y. Zhu, S. Hamid, D.
W. Bahnemann, Appl. Catal., B, 2017, 219, 611-618.
J. Zhang, S. Meng, X. Ye, C. Ling, S. Zhang, X. Fu, S. Chen, Appl.
Catal., B, 2017, 218, 420-429.
47 Y. Pan, Y. You, S. Xin, Y. Li, G. Fu, Z. Cui, Y. Men, F. Cao, S. Yu, and
J. B. Goodenough, J. Am. Chem. Soc., 2017, 139, 4123-4129.
48 Z. Huang, J. Song, X. Wang, L. Pan, K. Li, X. Zhang, L. Wang, J. Zou,
Nano Energy, 2017, 40, 308-316.
Q. Liu, H. Lu, Z. Shi, F. Wu, J. Guo, K. Deng, and L. Li, ACS Appl.
Mater. Interfaces, 2014, 6(19), 17200-17207.
5 X. Wang, S. Li, Y. Ma, H. Yu, J. Yu, J. Phys. Chem. C, 2011, 115(30),
4648-14655.
49 I. Poulios and N. Papadpoulos, Solar Energy Materials, 1990, 20, 43-
51.
1
6
C. Tan, G. Zhu, M. Hojamberdiev, K. S. Lokesh, X. Luo, L. Jin, J. Zhou,
50 V. Subramanian, E. E. Wolf, and P. V. Kamat, J. Am. Chem. Soc.,
2004, 126, 4943-4950.
P. Liu, J. Hazard. Mater. 2014, 278, 572-583.
7
L. Yuan, M. Yang, Y. Xu, J. Mater. Chem. A, 2014, 2(35), 14401-
51 P. Zhou, J. Yu, and M. Jaroniec, Adv. Mater., 2014, 26, 4920-4935.
1
4412.
52 G. Zhou, M. Wu, Q. Xing, F. Li, H. Liu, X. Luo, J. Zou, J. Luo, A. Zhang, Appl.
Catal. B-Environ, 2018, 220, 607–614.
This article is protected by copyright. All rights reserved.

ChemCatChem
10.1002/cctc.201801745
FULL PAPER
Entry for the Table of Contents
Zn3In2S6 was used to modify TiO2 based photocatalytic system, giving rise to a greatly improved reduction of CO2 into CO. The
ameliorated photocatalytic activity might be ascribable to Z-scheme electron transfer, resulting in dramatically enhanced separation
and transfer efficiencies of photo-induced electron-hole.
This article is protected by copyright. All rights reserved.