Soft-Chemical Method for Synthesizing Intermetallic Antimonide Nanocrystals from Ternary Chalcogenide

Article abstract of DOI:10.1021/acs.langmuir.9b01774

The synthesis of intermetallic antimonides usually depends on either the high-temperature alloying technique from high-purity metals or the flux method in highly poisonous Pb-melt. In this paper, we introduced a soft-chemical method to synthesize intermetallic antimonides from ternary chalcogenide precursors under an argon atmosphere below 200 °C. Powder X-ray diffraction and compositional analysis clearly indicate that a new phase of the Ag₃Sb nanocrystal was synthesized from the Ag₃SbS₃ precursors. Three types of trialkylphosphines (TAPs) were applied as desulfurization agents, and the transformation mechanism was elucidated. The capability of the desulfurization agent follows the sequence of triphenylphosphine (TPP) > tributylphosphine (TBP) > trioctylphosphine (TOP). Besides, this TAP-driven desulfurization route to synthesize the intermetallic phase could also be possible for AgSbSe₂ and Sb₂S₃. Therefore, this paper provides an efficient and mild technique for the fabrication of intermetallic nanocrystals.

Full text of DOI:10.1021/acs.langmuir.9b01774

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Interface Components: Nanoparticles, Colloids, Emulsions, Surfactants, Proteins, Polymers
Soft Chemical Method for Synthesizing Intermetallic
Antimonide Nanocrystals from Ternary Chalcogenide
Yilan Jiang, Long Yuan, Yanyan Xu, Jiaojiao Ma, Yu Sun, Xia Gao, Keke Huang, and Shouhua Feng
Langmuir, Just Accepted Manuscript • DOI: 10.1021/acs.langmuir.9b01774 • Publication Date (Web): 04 Nov 2019
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Soft Chemical Method for Synthesizing
Intermetallic Antimonide Nanocrystals from
Ternary Chalcogenide
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Yilan Jiang#, Long Yuan#, Yanyan Xu, Jiaojiao Ma, Yu Sun, Xia Gao, Keke Huang*, Shouhua
Feng
State Key Laboratory of Inorganic Synthesis and Preparative
Chemistry, College of Chemistry, Jilin University, Changchun
130012, People’s Republic of China
Key Laboratory of Functional Materials Physics and Chemistry of
the Ministry of Education, Jilin Normal University, Changchun
130103, People’s Republic of China
KEYWORDS:
Antimonide,
Desulfurization,
Synthesis,
Ternary
chalcogenide, Trialkylphosphine
ABSTRACT: The synthesis of intermetallic antimonides usually
depends on either the high temperature alloying technique from
high purity metals or the flux method in highly poisonous Pb-
melt. In this paper, we introduced a soft chemical method to
synthesize intermetallic antimonides from ternary chalcogenide
precursors under argon atmosphere below 200 °C. Powder X-ray
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diffraction and compositional analysis clearly indicate that a
new phase of Ag3Sb nanocrystal was synthesized from the Ag3SbS3
precursors. Three types of trialkylphosphine (TAP) were applied
as desulphurization agent and the transformation mechanism was
elucidated. The capability of desulphurization agent is followed
the sequence of triphenylphosphine (TPP) >tributylphosphine
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(TBP)
>trioctylphosphine
(TOP).
Besides,
this
TAP-driven
desulfurization route to synthesize intermetallic phase could
also be possible for AgSbSe2 and Sb2S3. Therefore, this paper
provides an efficient mild technique for the fabrication of
intermetallic nanocrystals.
INTRODUCTION
Antimonide-based
intermetallic
phase
compounds
receive
increasing concerns as important materials with interesting
physical properties (such as superconductivity and half-
metallity)
and
diverse
structural
chemistry
of
anionic
substructures1, that endow this family of materials potential
applications in magnetic material2, alloy-based anode materials
for Li-ion batteries3, catalysts4, and thermoelectric materials5.
Intermetallic antimonides are important members of nonclassic
Zintl phases, which are intermediate between 2-center-2-electron
with delocalized multicentre chemical bonding6. As one of the
most important antimonide-based intermetallic phase compounds,
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silver antimonides have been reported as anode materials for
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secondary lithium-ion batteries7,8 and Pb-free solder alloys9,10
.
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The alloy of antimonial silver has two members: dyscrasite (Ag3Sb)
and ε-phase of allargentum (Ag6Sb). The last phase has been found in
mineral that intimately intergrown with antimonial silver11.
Ag3Sb is the primary exsolution phase from Ag-Sb liquid alloys
according to a theoretical model12.
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The synthesis of intermetallic compounds is majorly dependent
on the alloying technique by mixing high purity metal as
starting
materials
at
high
temperature13.
However,
the
stoichiometry of Ag/Sb varies dependent on the preparation
temperature in alloying methods14. Single crystal of antimonide
intermetallic compound could be synthesized by high vacuum solid
state reaction15, the microwave‐assisted polyol process16 and Sn-
or Pb-flux method at over 900 oC17,18. High quality of Ag3Sb film
has only been reported under ultra-high vacuum conditions via
vapour epitaxy growth technique19. According to a previous study
on the formation phase boundaries of Ag3Sb, this phase is formed
at 562 oC with controlled stoichiometry20. Kulifay reported a low
temperature method for the synthesis of several intermetallic
compounds via a route of reducing metal cations by N2H4 • 2 HCl
and H3PO2, however, the resulted products are usually impure with
separated metal elements21. Zhao and Song et.al. have reported a
chemical reduction route to synthesize Ag-Sb composite by
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directly reducing the metal cations of Ag+ and Sb3+ by NaBH4,
however, it is difficult to control the degree of reductive
reaction and mixed phases of Sb element and Ag3Sb was obtained22.
Therefore, it still remains a great challenge to synthesize Sb-
based intermetallic phase nanocrystal with a convenient method
at ambient condition.
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Metal cations in sulphides are more mobile than that of
oxides due to the weak electronegativity of S2- than O2-, which
endows cation exchange reaction in-situ evolution in the crystal
lattice for synthesizing new controllable mixed phase sulphide
nanocrystals22. The phase selective extraction of Se and S from
nanoscale metal chalcogenides by TOP has been reported as an
effective
strategy
to
synthesize
less
S,Se/metal
ratio
nanomaterials23. Recently, Yu et. al. report
a
TAP-driven
chemical
transformation
route
to
synthesize
a
series
nanostructures of Ag, Bi metal and mixed sulphide nanocrystals
from Ag- or Bi-based sulphide precursors25. However, the research
on the complete desulfurization of ternary Sb-based sulphide
nanocrystals to synthetic Ag3Sb by cationic exchange has not been
studied.
In our previous work, we have generally studied the synthesis
of ternary Sb-based sulphide nanocrystals by hot-injection
method with various phases and morphologies26. In this paper, we
report a method to synthesize antimonide-based intermetallic
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Ag3Sb nanocrystal by ternary sulphide nanocrystal. The conversion
of Ag3Sb intermetallic nanocrystal from Ag3SbS3 was conducted in
a mild condition at ambient pressure below 200 oC. PXRD and TEM
results clearly indicate the desulfurization. Three types of TAP
were applied as desulfurization agent and the transformation
mechanism was elucidated. The capability of desulfurization
agent is followed the sequence of TPP > TBP > TOP. Besides, the
TAP-driven desulfurization method could also be used to retract
metal phase from AgSbSe2 and Sb2S3. The intermetallic phase
extraction route illustrated in paper provides a fundamental
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understanding
and
practical
method
for
synthesis
of
intermetallic nanocrystal.
EXPERIMENTAL SECTION
Chemicals. Silver nitrate (AgNO3, 99.8 %) was purchased from
Sinopharm Chemical Reagent Co.Ltd. Sublimed sulfur (S, 99.5 %),
selenium (Se, 99.9 %), oleylamine (OLA, 90 %), TPP, TBP and TOP
were obtained from Aladdin. Antimony (III) trichloride (SbCl3,
99.0 %), sodium diethyldithiocarbamatetrihydrate（ Na(S2CNEt2)·
3H2O, 98 %), 1-octa-decene (ODE, 90%) and oleic acid (OA, 90 %)
were purchased from Alfa AesarCo., Inc. Hexane (99.7 %, A.R.)
and ethanol (95.5 %, A.R.) were Beijing Chemical Industrial
Group Co., Ltd. All chemicals were directly used without any
further purification.
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Synthesis of Sb(S2CNEt2)3 precursor. Sb(S2CNEt2)3 was prepared as
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followed
procedure.
10
mmol
of
SbCl3
and
30
mmol
of
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Na(S2CNEt2)·3H2O were dissolved respectively in absolute ethanol.
Then both of solutions were mixed and kept stirring for 30 min.
The yellow precipitate was isolated through filtration, then
washed with H2O and dried at 60 oC.
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Preparation of Ag3SbS3 nanocrystals. The hot-injection route
synthesis of Ag3SbS3 nanocrystals followed our previous work27. In
a typical procedure, 3 mmol of AgNO3, 1 mmol of SbCl3 and 3 mmol
S powders were added into a 100 mL three-necked flask containing
ODE (8 mL), OLA (4 mL) and OA (2 mL) at room temperature. Then
the mixture was degassed at 80-110 oC for removing water and the
low boiling point impurities under vacuum for 20 min. The
solution was heated up to 190 oC under an Ar atmosphere and kept
for 1 h, during which the color of the mixture appeared yellow-
orange. Then the resulting solution was cooled naturally at room
temperature. Afterwards, Ag3SbS3 nanocrystals were dispersed and
precipitated respectively using toluene and ethanol, and
centrifugation was followed. The samples were purified several
cycles and dried under vacuum condition.
Preparation of Ag3Sb nanocrystals. In order to obtain the Ag3Sb
nanocrystals, 5 mL of OLA and 300μL (or 0.3 g) of TAP were added
into the three-necked flask containing 25 mg of as-prepared
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Ag3SbS3 nanocrystals at room temperature. Then the following
procedure was same as that for the Ag3SbS3 nanocrystals.
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Preparation of AgSbSe2 nanocrystals. In a typical procedure,
1mmol of AgNO3, 1 mmol of SbCl3 and 2 mmol Se powders were added
into a 100 mL three-necked flask containing ODE (8 mL), OLA (1
mL) and OA (1 mL) at room temperature. Then the mixture was
degassed at 80-110 oC under vacuum for 20 min. The solution was
heated up to 200 oC under an Ar atmosphere for 1 h. Then, the
resulting solution was cooled naturally. Ethanol was added to
precipitate the AgSbSe2 nanocrystals and centrifugation was
followed. The samples were purified several cycles by using
toluene and ethanol, and dried under vacuum condition, finally.
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Chemical Transformation of AgSbSe2 nanocrystals to Ag3Sb and Sb.
In a typical procedure, 25 mg of as-prepared AgSbSe2 nanocrystals
and 0.3g TPP were dispersed in 5 mL OLA in a 100 mL three-necked
flask. The mixture was degassed at 90 oC and heated up to 190 oC
under Ar and kept for 1 h.
Preparation of Sb2S3 nanocrystals and desulfurize to Sb. The
above mentioned Ag3SbS3 experimental procedure was also followed
for the prepare of Sb2S3 nanocyrstals, except that the material
was Sb(S2CNEt2)3 and the solvent ratio was tuned to OLA:OA:ODE=
2:1:2. The desulfurization process for Sb2S3 nanocrystals is
followed the same procedure as that of AgSbSe2.
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Characterization. The crystal structures of the as-prepared
products were investigated by powder X-ray diffraction (XRD,
D/MAX2550, Rigaku, Japan) with graphite monochromic Cu Kα
radiation. The 2θ range was 10-80°, and the scan speed was
3°/min. The microstructures were characterized by transmission
electron microscopy (TEM, Tecnai G2S-Twin F20, FEI, Holland) and
the scanning electron microscopy (SEM, Helios NanoLab 600i, FEI,
Holland). X-ray photoelectron spectra (XPS) were acquired to
analyze the surface composition of materials with an ESCALAB
250Xi electron energy spectrometer from Thermo company, and Al
Kα (1486.6 eV) served as the X-ray excitation source.
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RESULTS AND DISCUSSION
Synthesis of Ag3Sb by desulfurization from ternary sulfide
Ag3SbS3
nanocrystals.
Ag3SbS3
precursor
nanocrystals
were
synthesized follows our previous work.27 Intermetallic Ag3Sb
nanocrystals were obtained by treated Ag3SbS3 with various TAP
solutions. As shown in Figure 1, Ag3SbS3 presents the typical
diffraction peaks of trigonal structure (pyrargyrite phase with
JCPDS card No. 74-1875) and the the space group of it is R 3c.
After been treated with TPP for 1 h, S in Ag3SbS3 was removed to
form Ag3Sb. The as-synthesized Ag3Sb shows a high purity phase.
The diffraction peak positions and their intensities match well
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with the simulated pattern of orthorhombic structure of Ag3Sb
(simulated from a CIF file with ICSD #52600). The space group of
Ag3Sb is Pmmn with its lattice parameter of a=5.99 Å, b=4.85 Å,
c=5.24 Å,
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Figure 1. PXRD pattern of TPP-0 min and TPP-60 min.
respectively.
No
distinguishable
diffraction
peaks
from
secondary phases of Ag- or Sb-species could be observed in the
XRD patterns of the pattern, suggesting that the as-synthesized
Ag3Sb nanocrystals are pure phase.
Shown in Figure 2a is the SEM graph of Ag3SbS3 while Figure 2b
is as-synthesized Ag3Sb nanocrystals obtained by TPP treatment.
The size of Ag3Sb is larger than that of Ag3SbS3 nanocrystals and
no definite morphology for each Ag3Sb nanocrystals, which is due
to the imbalance in different treatment conditions of TAP
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solutions and reaction temperatures. The EDS results show that
the obtained sample contains only two elements, Ag and Sb, and
the atomic ratio of the two elements is about 3:1, indicating
that pure Ag3Sb is obtained.
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High-resolution XPS spectra of Ag 3d and Sb 3d for the as-
prepared Ag3Sb sample are obtained using C 1s as the reference at
284.6 eV, as shown in Figure 3. Peaks of Ag 3d3/2 and 3d5/2 of
Ag3Sb locate at 374.05 and 368.02 eV, respectively, which is
higher than that of
Figure 2. (a) SEM image of Ag3SbS3, (b) SEM image of Ag3Sb, (c)
EDS of Ag3Sb obtained by TPP treated Ag3SbS3 nanocrystal
precursors.
Ag3SbS3 (373.9 eV for Ag 3d5/2 and 367.8 eV for Ag 3d3/2). Also,
the binding energy peaks for Sb of Ag3Sb is higher than Ag3SbS3,
which is located at 539.60 and 530.30 eV for Sb 3d5/2 and Sb
3d3/2, respectively. On the one hand, these results indicate a
nearly zero valance state of Ag and Sb as an intermetallic phase
of the as-synthesized compound.28 On the other hand, we can also
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learn that the bonding force between Ag and Sb is enhanced after
desulfurization.
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Figure 3. XPS spectra of Ag3Sb with the element binding energy of
Ag 3d and Sb 3d, respectively.
Effect on Desulfurization. Three types of TAP (i.e. TOP, TPP and
TBP) were adopted to desulfurize from ternary sulfide Ag3SbS3
nanocrystal precursors with various treatment time. When ternary
sulfide treated in TOP for 10 min (TOP-10 min), the XRD pattern
shows that it remains Ag3SbS3 (JCPDS card No. 74-1875) with a
weak sign of getting Ag3Sb as shown in
Figure 4. Treatment time of TOP on the formation of Ag3Sb.
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Figure 4. When been treated with TOP up to 60 min (TOP-60 min),
a clear set of diffraction peaks of Ag3Sb phase is shown with a
slight amount of Ag3SbS3 phase, which indicates that the sulfur
in Ag3SbS3 nanocrystal has been etched from the ternary sulfide
crystal lattice with the assistance of TOP molecule.
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SEM graphs of Ag3SbS3 nanocrystals treated by TOP show clear
particle size reduction due to the selective removal of S from
Ag3SbS3 lattice (Figure 5). The particle size (c.a. 200 nm in
length) and shape of TOP-10 min is near with that of as-
synthesized Ag3SbS3 nanocrystals. For the samples treated for 60
min, however, the particle size of TOP-60 min is c.a. 50 nm.
Nanorod morphology in the SEM graphs of Figure
5
is also
ascribed to the Ag3Sb phase, because of no secondary phase could
be determined from PXRD results. According to Bravais-Friedel-
Donnay-Harker theory, crystal growth speed along different
directions is proportional to the inverse of crystal lographic
plane distances, i.e. the smallest dhkl value position of (010)
is
18.49o, with a d010 of
4.85 Å, grow the fastest that will
diminish in the final crystal morphology29,30. While the peak
position of (100) and (001) locates at 14.78o and 16.91o, which
corresponded to a d100 and d001 value of 5.99 and 5.24 Å. This
structure characteristic of Ag3Sb indicates a
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Figure 5. SEM of Ag3Sb obtained by TOP treated Ag3SbS3
nanocrystals with different times of 10 min and 60 min,
respectively.
preferential growth orientation is <010> direction with the
retard growth along <001> and <100>, that may lead to a rod-like
morphology of the ideal growth in final products.
For comparison, the same ternary sulfide nanocrystal sample was
also treated with TBP for 60 min (TBP-60 min) as shown in Figure
6. Combined with the XRD spectrum of TPP-60 min, it can be seen
that pure phase of Ag3Sb could be obtained via both TPP and TBP
solvent. Also, SEM graph of TBP-60 min is shown in the inset of
Figure 6. Compared with the particle size of TPP-60 min, which
shown in Figure 2b, TBP-60 min is smaller. Average particle size
of TPP-60 min and TBP-60 min is 350 nm and 172 nm, respectively,
which is much larger than that of TOP-60 min. Both of the Ag3Sb
samples show no definite shape of crystal, which may due to the
imbalance in ion diffuse in the TAP solvents.
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Moreover, we used TPP to treat Ag3SbS3 for 15, 30, 45, 60 min
to better explore the effects of samples over time. This is
because the sample obtained by TPP is the most easily observed
due to since the obtained samples is larger than others.
According to the PXRD pattern from Figure S1, we can see that
the phase of Ag3Sb appears when treated with TPP for 15 min. The
phase of Ag3SbS3 is completely converted to phase Ag3Sb at 30
minutes. Continue to extend the time of TPP processing, Ag3Sb
phase remains unchanged. As shown in Figure S2, the particle
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Figure 6. PXRD of Ag3Sb which obtain by treated Ag3SbS3 with TBP
for 60min and the inset is the SEM image of TBP-60 min.
size and shape of Ag3SbS3-TPP-15 min are similar to that of as-
synthesized Ag3SbS3 nanocrystals. When been treated for 30
minutes, the sample gradually became larger and
a
rod-like
structure appeared, which was similar to the sample treated with
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TOP. The SEM images of the obtained Ag3Sb nanocrystals show
significant aggregation as the treatment time continue to extend
(Figure S2). High-resolution XPS spectra of Ag 3d, Sb 3d and S
2p for the samples are obtained using C 1s as the reference at
284.6 eV, as shown in Figure S3. After Ag3SbS3 is treated with
TPP, the peaks of Ag and Sb gradually move toward higher binding
energy, indicating that the bonding force between Ag and Sb is
enhanced, and the peak of S gradually disappears, indicating of
the process of desulfurization.
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To check the effectiveness of the method to synthesize Ag3Sb
intermetallic phase nanocrystal, we also applied this method to
treat AgSbSe2 nanocrystals. As shown in Figure S4a, PXRD result
show the AgSbSe2 is pure phase (JCPDS #12-0379). After been
treated with TPP for 60 min, it shows clear evidence of the
deselenium from ternary chalcogenide phase with the main product
of Ag3Sb and some impurity of Sb element (JCPDS card No. 35-
0732). Shown in Figure S4b is the SEM image of AgSbSe2, the rod-
like shape is obtained by the synthetic method. However, Ag3Sb
sample obtained from AgSbSe2 shows no definite shape of crystal
(Figure S4c), which may due to the imbalance in ion diffuse in
the TPP solvents. The desulfurization effect is also possible
shown in TPP treated Sb2S3 as shown in Figure S5. The primary
synthesized Sb2S3 shows the typical diffraction peaks of
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orthorhombic structure (JCPDS #42-1393) and the space group of
it is Pbnm (Figure S5a). After treated with TPP for 60 min, it
changes into trigonal structure (space group is R 3m), which
corresponded to Sb phase (JCPDS #42-1393). SEM images in Figure
S6 show that the samples agglomerated before and after treatment,
and the size of ions decreased slightly after treatment. This
result indicates that the de-chalcogenide method by TAP could be
applied to synthesize most of Sb-based intermetallic alloys from
their multi-chalcogenide precursors.
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Mechanism for desulfurization from ternary sulfide. In order to
understand the mechanism of desulfurization effect of TAP from
ternary sulfide nanocrystal, the molecule structure and function
should be analyzed in advance. In our experiment, three types of
TAP have been used to etch S2- or Se2- from Ag3SbS3 and AgSbSe2
precursors. They are all characterized with 4 sp3 hybrid orbitals
with 3 of them bonded with different alkyl groups, i.e. butyl-,
octyl- and phenyl-group. The un-bonded orbital of P is occupied
with one pair of lone electrons, which endows the reductive
properties of TAP in most of chemical reactions. TOP has been
regarded as an promoter to enhance cation exchange processes due
to its strong binding affinity to Cu(I)31. The desulfurization
capability of TAP is mainly dependent on this binding effect to
Ag and Sb in the ternary chalcogenide in our experiment. Factors
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that determine the capability of TAP are dominated by the alkyl
group that bonding to center P-atom through steric hindrance
effect and
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Figure 7. Molecule structure of three types of TAP.
charge transfer effect. Octyl-group is a long chain of –(CH2)7-
CH3, which may hinder the interaction between the sole pair
electrons of sp3 hybrid P with Ag or Sb in the crystal lattice of
Ag3SbS3. Phenyl-group is a phenyl ring with delocalized electrons
from conjugated orbital of the sp2 hybrid C atoms, which may
provide additional electrons that could transfer to the orbital
of sp3 hybrid P atom to increase its electron negativity and
binding affinity to metal cations in ternary chalcogenide
nanocrystals. Butyl-group is a short akyl-chain of –(CH2)3-CH3,
that neither such strong steric effect to lower its affinity,
nor electron transfer effect to increase its negativity.
According to the desulfurization process in our experiment,
the strongest desulfurization agent of TAP is TPP, followed by
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TBP, and weakest TOP. For the same Ag3SbS3 nanocrystal precursor
treatment with same time, TPP results in poorly crystalized
Ag3Sb; TBP results in the samples with good crystallinity; and
TOP results in the mixture of unreacted Ag3SbS3 and Ag3Sb
intermetallic phase. In order to understand the transformation
mechanism from Ag3SbS3 to Ag3Sb, ex-situ TEM was measured for the
untreated Ag3SbS3 and treated samples with increasing time from
10 min to 4 h as shown in Figure 8. Ag3SbS3 sample with the
initial morphology of tetrahedral shape nanocrystals was used to
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discriminate
the
morphology
evolution
process.
Typical
tetrahedral structure shape nanocrystal with rounded corners is
shown in Figure 8a. The surface of the nanocrystal is smooth
without any other particle attachment. After this sample is
treated with TOP for 10 min, small particles were grown on the
surface of the Ag3SbS3 nanocrystal, which can be seen in Figure
8b marked with red circle. The Ag3Sb phase grows gradually with
the increasing the interaction between TOP and Ag3SbS3 that
induced to a rod morphology of the intermetallic phase (Figure
8c). After treatment of Ag3SbS3 in TOP for 4 h, the shape of
Ag3Sb is consisted with long nanorod and small nanoparticles
(Figure 8d). These results are in agreement with the PXRD in
previous discussions of this paper. In addition, HRTEM results
of Ag3SbS3 show typical (211) and (110) crystal plane distances
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of 0.33 and 0.55 nm, respectively, (Figure 8e) while Ag3Sb shows
(021) and (200) crystal plane
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Figure 8. Ex-situ TEM graphs of time dependent desulfurization
processes from Ag3SbS3 to Ag3Sb treated in TOP. (a) Ag3SbS3
nanocrystal, Ag3SbS3 treated with TOP for (b) 10 min, (c) 1 h,
and (d) 4 h, respectively. Red circles in (b) and (c) are
indicated to show the Ag3Sb-decorated Ag3SbS3 nanocrystals. Blue
circle indicates the formation of Ag3Sb rod after treatment with
TOP for 1 h. (e) HRTEM of Ag3SbS3 (f) HRTEM of TOP-60 min, (g)
Schematic of the transformation process from Ag3SbS3 to Ag3Sb by
the desulfurization effect of TAP. Ag: grey balls; Sb: red
balls; S: blue balls. (h) Reaction of TAP with Ag3SbS3.
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distances of 0.22 and 0.30 nm, respectively. (Figure 8f) In
comparison, the chemical formula of Ag3SbS3 and Ag3Sb could
simply subtract S from the former compound.
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For clarity, the crystal unit cell structure of Ag3SbS3 and
Ag3Sb were plotted in Figure 8g. Ag3SbS3 is known as the mineral
name of pyrargyrite that crystalized into a trigonal crystal
system with a space group of R 3c (161). In each unit cell of
Ag3SbS3, there are six Ag3SbS3 isolated unit with Sb occupied at
6a-site, Ag 18b-site and S 18b-site in Wyckoff’s position system.
The bond length is 2.4609 Å for Sb-S, and 2.4249 Å and 2.4613 Å
for Ag-S, respectively. In the lattice of Ag3SbS3, Sb atoms
mainly occupied at the corner of each unit cell with the other
Sb and Ag inserted that weakly bonded with S2- nominally. With
the assistance of the desulfurization from TAP, S is getting
removed from the lattice of Ag3SbS3, and the remaining metal
atoms
crystalized
into
an
intermetallic
phase
of
Ag3Sb
simultaneously. The crystal structure of Ag3Sb is orthorhombic
with a space group of Pmmn. The position of Sb in Ag3Sb lattice
is also at the corner of the unit cell (1a-site in Wyckoff’s
notation), with three sites for Ag atoms inside of the crystal
lattice, which could be found as a primary model from Ag3SbS3
lattice with slightly adjustment of the crystal lographic
position after S extraction. Therefore, the transformation from
Ag3SbS3 to Ag3Sb with the assistance of TAP is possible. Reaction
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of TAP with Ag3SbS3 is showed in Figure 8h. Combined with
previous research,[32-35] we speculate that TAP react with Ag3SbS3
to give trialkylphosphane sulfide by elimination of one alkyl
substituent, and Ag3Sb generated at the same time.
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CONCLUSIONS
In summary, we have performed the first example of
transformation
of
ternary
antimonite
chalcogenide
into
intermetallic phase by the extraction effect of TAP under Ar
oC.
atmosphere
below
200
Powder
x-ray
diffraction
and
compositional analysis clearly indicate that a new phase of Ag3Sb
nanocrystal was synthesized from the Ag3SbS3 precursors. Three
types of TAP were applied as desulfurization agent and the
transformation mechanism was elucidated. The capability of
desulfurization agent is followed the sequence of TPP > TBP >
TOP.
Besides,
this
TAP-driven
desulfurization
route
to
synthesize intermetallic phase could also be possible for AgSbSe2
and Sb2S3. This paper illustrates an efficient and safe technique
for the preparation of intermetallic nanocrystals.
ASSOCIATED CONTENT
Supporting Information.
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Additional information including PXRD, SEM and of treatment time of TPP on the
formation of Ag3Sb. PXRD result and SEM graph of octahedral shape
Ag3Sb nanocrystal from the deselenium of AgSbSe2. PXRD and SEM graph
of Sb2S3 and desulfurized phase of Sb2S3 nanocrystals.
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AUTHOR INFORMATION
Corresponding Author
*E-mail: kkhuang@jlu.edu.cn
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENT
This work was supported by the National Natural Science Foundation of China (Grant Nos.
21671076, 21427802).
Author Contributions
# Y. Jiang and L. Yuan contributed equally to this work.
REFERENCES
(1) Mills, A. M.; Deakin, L.; Mar, A. Electronic Structures and
Properties of RE12Ga4Sb23 (RE = La-Nd, Sm) and Superconducting
La13Ga8Sb21.Chem. Mater.2001, 13, 1778-1788.
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1
2
3
4
(2) Chen, X.; Shen, J. N.; Wu L. M.; Chen, L. A Ferrimagnetic
5
6
Zintl
Phase
Pr4MnSb9:
Synthesis,
Structure,
and
Physical
7
8
Properties. Inorg. Chem. 2013, 52, 7441-7447.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(3) Park, C. M.; Kim, J.-H.; Kim, H.; Sohn, H.-J. Li-alloy
based anode materials for Li secondary batteries. Chem. Soc. Rev.
2010, 39, 3115-3141.
(4) Bauer, J. C., Chen, X.; Liu, Q.; Phan, T. H.; Schaak, R. E.
Converting nanocrystalline metals into alloys and intermetallic
compounds for applications in catalysis. J. Mater. Chem. 2008,
18, 275-282.
(5) Tan, G.; Zhao, L. D.; Kanatzidis, M. G. Rationally
Designing High-Performance Bulk Thermoelectric Materials. Chem.
Rev. 2016, 116, 12123-12149.
(6) Xia S. Q.; Bobev, S. Cation-Anion Interactions as Structure
Directing Factors: Structure and Bonding of Ca2CdSb2 and Yb2CdSb2.
J. Am. Chem. Soc. 2007, 129, 4049-4057.
(7) Vaughey, J. T.; Fransson, L.; Swinger, H. A.; Edström, K.;
Thackeray, M. M. Alternative anode materials for lithium-ion
batteries: a study of Ag3Sb. J. Power Sources. 2003, 119-121, 64-
68.
ACS Paragon Plus Environment
23

Langmuir
Page 24 of 29
1
2
3
4
5
6
7
8
(8) Zhang,W. J. A review of the electrochemical performance of
alloy anodes for lithium-ion batteries. J. Power Sources. 2011,
196, 13-24.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(9)
Masson,
D.
B.;
Kirkpatrick,
B.
K.
Equilibrium
solidification of Sn-Ag-Sb thermal fatigue-resistant solder
alloys.J. Electron. Mater.1986, 15, 349-353.
(10) Lee, H. T.; Chen, M. H.; Jao, H. M.; Hsu, C. J. Effect of
adding Sb on microstructure and adhesive strength of Sn-Ag
solder joints. J. Electron. Mater. 2004, 33, 1048-1054.
(11) Somanchi, S.; Clark, L. A. The occurrence of Ag6Sb phase at
Cobalt, Ontario. The Canadian Mineralogist. 1966, 8, 610-619.
(12) Singh, B. P.; Adhikari, D.; Jha, I. S. Concentration
dependence of the structure and thermodynamic properties of
silver–antimony alloys. J. Non-Crystalline Solids. 2010, 356,
1730-1734.
(13) Ruan, Y.; Wang, N.; Cao, C.; Wei, B. Rapid solidification
mechanism of Ag60Sb34Cu6 ternary alloy in drop tube. Chin. Sci.
Bull. 2004, 49, 1801-1805.
(14) Somanchi,S. Subsolidus phase relations in the system Ag-Sb.
Canadian J. Earth Sci. 1966, 3, 211-222.
ACS Paragon Plus Environment
24

Page 25 of 29
Langmuir
1
2
3
4
5
6
7
8
9
(15) Zheng,W. Z.; Wang, P.; Wu, L. M.; Chen, L. Synthesis,
Crystal and Electronic Structures, and Physical Properties of
Caged Ternary Cu-Rich Antimonide: BaCu7.31(3)Sb5. Inorg. Chem. 2010,
49, 7491-7496.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(16) Teichert, J.; Heise, M.; Chang, J. H.; Ruck, M. Refinement
of the Microwave ‐ Assisted Polyol Process for the Low ‐
Temperature Synthesis of Intermetallic Nanoparticles. Eur. J.
Inorg. Chem. 2017, 42, 4930–4938
(17) Hu, Y.; Chen, C. W.; Cao, H.; Makhmudov, F.; Grebenkemper,
J. H.; Abdusalyamova, M. N.; Morosan, E.; Kauzlarich, S. M.
Tuning Magnetism of [MnSb4]9- Cluster in Yb14MnSb11 through
Chemical Substitutions on Yb Sites: Appearance and Disappearance
of Spin Reorientation. J. Am. Chem. Soc. 2016, 138, 12422-12431.
(18) Zhu, M.; Tan, W.; Wu, Z.; Tao, X. T.; Huang, B.; Xia, S. Q.
Sr4Cu25.37(18)Sb12
and
Eu4Cu26.06(13)Sb12:
Copper-Rich
AntimonideIntermetallics with Cage Structure. Cryst. Growth Des.
2018, 18, 1722-1729.
(19) Gardiner, T. M.; Stiddard, M. H. B. Epitaxial growth and
stabilization of the compound Ag3Sb on silver {1 1 1}. J. Mater.
Sci. 1981, 16, 1522-1526.
ACS Paragon Plus Environment
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Langmuir
Page 26 of 29
1
2
3
4
5
6
7
8
(20) Feschotte, P.; Monachon, F.; Durussel, Ph. The binary
system Sb-Ag: a revision of the Ag3Sb phase boundaries. J. Alloy
Comp. 1992, 186, L17-L18.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(21) Kulifay,S. M. A Low Temperature Synthesis for Powder-form
Intermetallics and Other Compounds. J. Am. Chem. Soc. 1961, 83,
4916-4919.
(22) Wang, F.; Yao, G.; Xu, M.; Zhao, M.; Zhang, P.; Song, X.
Ag-Sb composite prepared by chemical reduction method as new
anode materials for lithium-ion batteries.Mater. Sci. Engineer.
B. 2011, 176, 442-445.
(23) Luther, J. M.; Zheng, H.; Sadtler, B.; Alivisatos, A. P.
Synthesis of PbS nanorods and other ionic nanocrystals of
complex morphology by sequential cation exchange reactions. J.
Am. Chem. Soc. 2009, 131, 16851-16857.
(24) Sines I. T.; Schaak, R. E. Phase-Selective Chemical
Extraction
of
Selenium
and
Sulfur
from
Nanoscale
Metal
Chalcogenides: A General Strategy for Synthesis, Purification,
and Phase Targeting. J. Am. Chem. Soc. 2011, 133, 1294-1297.
(25)
Han,
S.
K.;
Gu,
C.;
Gong,
M.;
Yu,
S.
H.
A
Trialkylphosphine-Driven Chemical Transformation Route to Ag-
and Bi-Based Chalcogenides. J. Am. Chem. Soc. 2015, 137, 5390-
5396.
ACS Paragon Plus Environment
26

Page 27 of 29
Langmuir
1
2
3
4
5
6
7
8
9
(26) Liang, Q.; Huang, K.; Ren, X.; Zhang, W.; Xie R.; Feng, S.
Synthesis of Cu-Sb-S nanocrystals: insight into the mechanism of
composition and crystal phase selection. CrystEngComm. 2016, 18,
3703-3710.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(27) Xu,Y.; Yuan, L.; Xie, R.; Wang, L.; Liang, Q.; Geng,
Z.;Liu, H.; Huang, K. Shape Control of Ternary Sulfide
Nanocrystals. Cryst. Growth Des. 2018, 18, 864-871.
(28) Naumkin, A.; Anna Kraut-Vass, V.; Gaarenstroom, S. W.;
Powell, C. J. NIST X-ray Photoelectron Spectroscopy Database,
NIST Standard Reference Database 20, Version 4.1, 2012.
(29) Yuan, L.; Huang, K.; Wang, S.; Hou, C.; Wu, X.; Zou, B.;
Feng, S. Crystal Shape Tailoring in Perovskite Structure Rare-
Earth Ferrites REFeO3 (RE = La, Pr, Sm, Dy, Er, and Y) and Shape-
Dependent Magnetic Properties of YFeO3. Cryst. Growth Des. 2016,
16, 6522-6530.
(30) Wang, S.; Wu, X.; Yuan, L.; Zhang, C.; Lu, D.
Shapetuneable synthesis of perovskite structured rare-earth
chromites RECrO3via a mild hydrothermal method. CrystEngComm.
2017, 19, 6436-6442.
(31) van der Stam, W.; Bladt, E.; Rabouw, F. T.; Bals, S.; de
Mello Donega, C. Near-Infrared Emitting CuInSe2/CuInS2 Dot
ACS Paragon Plus Environment
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Langmuir
Page 28 of 29
1
2
3
4
5
6
Core/Rod Shell Heteronanorods by Sequential Cation Exchange. ACS
Nano. 2015, 9, 11430-11438.
7
8
9
(32) Zhang, T.; Schwedtmann, K.; Weigand, J. J.; Doert, T.;
Ruck, M. Dissolution behaviour and activation of selenium in
phosphonium based ionic liquids. Chem. Commun. 2017, 53, 7588-
7591.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
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53
54
55
56
57
58
59
60
(33) Zhang, T.; Schwedtmann, K.; Weigand, J. J.; Doert, T.;
Ruck, M. Understanding the Chemical Reactivity of Phosphonium‐
Based Ionic Liquids with Tellurium. Chem. Eur. J. 2018, 24,
9325–9332.
(34) Kaiser, M.; Rasche, B.; Ruck, M. The Topochemical
Pseudomorphosis of a Chloride into a Bismuthide. Angew. Chem.
Int. Ed. 2014, 53, 3254–3258.
(35) Kaiser, M.; Baranov, A. I.; Ruck, M. Bi2Pt (hP9) by Low‐
Temperature Reduction of Bi13Pt3I7: Reinvestigation of the Crystal
Structure and Chemical Bonding Analysis. Z. Anorg. Allg. Chem.
2014, 640, 2742–2746.
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