Supporting Information
Liquid-Solid-Solution Synthetic Strategy to Nearly
Monodisperse Nanocrystals
Xun Wang, Jing Zhuang, Qing Peng, Yadong Li*
Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
National Center for Nanoscience and Nanotechnology, Beijing, 100084, P. R. China
Corresponding Author: ydli@tsinghua.edu.cn
Part I
Particle size distributions analysis of the nanocrystals (Page 2~8; Supplementary
Figure 1~18)
Part II
EDS analysis of the nanocrystals; (Page 9~19; Supplementary table 1; Supplementary
Figure 19~37)
Part III
Detailed experimental conditions for distinct class of nanocrystals with certain
composition and sizes (Page 20~23; Supplementary table 2; Supplementary Figure
38~41)
Part IV
Nanocrystals obtained by employing different solvents instead of ethanol (Page 24~25;
Supplementary Figure 42~44)
Part V
Magnetic characterization of MFe2O4 (M=Fe, Co, Mn, Mg, Zn) nanocrystals; Uv-vis
spectra of Ag nanocrystals with different sizes; Visible-to-naked-eyes green
upconversion emissions from NaYF4 nanocrystals (Page 26~28; Supplementary
Figure 45~49)
Part VI
Synthesis
and
characterization
Supplementary Figure 50~66)
of
New-type
Nanocrystals
(Page
29~38;
Part I
Particle size distribution analysis of the nanocrystals
Supplementary Figrue1.
Fig 1A Ag nanocrystals (6.1±0.3 nm; sd =4.9%)
300 particles are measured to get the size distribution.
S Fig. 2 Fig 1A Rh nanocrystals (2.2 ±0.1 nm, sd 4.5%)
300 particles are measured to get the size distribution.
S Fig.3 Low magnification TEM images of Ir nanocrystals (Fig 1A) (1.7 ±0.09 nm;
sd 5.2%)
The statistics are made on the low-magnification TEM images of Ir nanocrystals as
shown below. 300 particles are measured to get the size distribution.
S Fig.4 Fig 1A Au nancorystals Au (7.1± 0.5nm, sd 7%)
300 particles are measured to get the size distribution.
S Fig.5 Fig 1B Ag2S nanocrystals (7.3±0.4nm; sd 5.5%)
200 particles are measured to get the size distribution.
S Fig.6 Fig 1B PbS nanocrystals (5.7 ±0.2nm, sd 4%)
300 particles are measured to get the size distribution.
S Fig.7 Fig 1B CdSe nanocrystals (7.1±0.8nm; sd 11%)
300 particles are measured to get the size distribution.
S Fig.8 Fig 1B ZnSe nanocrystals (8.2± 0.9nm, sd 11%)
200 particles are measured to get the size distribution.
S Fig.9 Fig 1C Fe3O4 nanocrystals (9.1 ± 0.7nm, sd 7%)
200 particles are measured to get the size distribution.
S Fig.10 Fig 1C CoFe2O4 nanocrystals (11.5± 0.6 nm; sd = 5%)
300 particles are measured to get the size distribution.
S Fig.11 Fig 1C TiO2 nanoceystals (4.3 ±0.2 nm, sd 4.6%)
300 particles are measured to get the size distribution.
S Fig.12
Fig 1C BaTiO3 nanocrystals (16.8 ± 1.7nm, sd=10.7)
160 particles are measured to get the size distribution.
S Fig.13 Fig 1D NaYF4 nanocrystals (10.5 ± 0.7nm; sd=6.7%)
300 particles are measured to get the size distribution.
S Fig.14 Fig 1D LaF3 nanocrystals (8.0±0.3nm; 3.7%)
300 particles are measured to get the size distribution.
S Fig.15 Fig 1D YbF3 nanocrystals (9.5 ± 0.6 nm; sd = 6.3%)
300 particles are measured to get the size distribution.
S Fig.16 Fig 1E PPy nanocrystals (4.2 ± 0.5nm)
300 particles are measured to get the size distribution.
S Fig.17 Fig 1E PAn nanocrystals (3.3 ±0.5nm)
300 particles are measured to get the size distribution.
S Fig.18 Fig 1E Copper Phthalocyanine nanocrystals (0.8 ±0.1nm)
200 particles are measured to get the size distribution.
Part II
EDS analysis of the nanocrystals
Besides XRD structural characterization, EDS element analysis have been performed
on the as-obtained nanocrystals, and under optimal experimental conditions,
functional nanocrystals with stoichiometry as revealed from their molecular formula
can be readily prepared.
Due to the detecting limitation of the EDS technique, elements with smaller atomic
weight (for example, O and F) cannot be detected, and their compositions are
determined by elemental analysis or XRD data. The experimental uncertainty is about
3-5%. All the peaks of the Cu elements are from the copper TEM grids.
Supplementary Table 1
Samples
Atomic ratios
Ag
Ag 100% (taken from Fig1A,
and 120 and 180oC samples,
respectively)
Au
Au100% (taken from Fig1A, and
other 3 samples obtained at
different temperatures of 100C,
20oC, 60oC)
Ir
Ir 100% (taken from Fig1A, and
other 2 samples obtained at
different temperatures of 1800C,
and 90oC)
Rh
Rh 100%(taken from Fig1A, and
other 2 samples obtained at
different temperatures of 1800C,
and 90oC)
Ru
Ru 100%(taken from 3 samples
obtained
at
different
temperatures of 80, 120 and
200oC)
CdSe
Typically Cd:Se=49:51 (taken
from Fig 1B and other 2 samples
obtained at a temperature
conditions of 140oC and 200oC,
SeO3- as Se sources)
Cd:Se ≈1:1 when Se powder was
adopted as Se sources and
temperature was kept above
140oC.
ZnSe
Zn:Se = 48:52; (taken from Fig
1B and other 2 samples obtained
at a temperature conditions of
Instrument
JEOL
JEM-2010F
HRTEM;
(Uncertainty=1~2%); Hitachi H-800
TEM (Uncertainty =3~5%)
Hitachi H-800 TEM (Uncertainty
=3~5%)
Hitachi H-800 TEM (Uncertainty
=3~5%)
Hitachi H-800 TEM (Uncertainty =3~
5%)
JEOL
JEM-2010F
HRTEM;
(Uncertainty=1~2%); Hitachi H-800
TEM (Uncertainty =3~5%)
Hitachi H-800 TEM (Uncertainty =3~
5%)
Hitachi H-800 TEM (Uncertainty =3~
5%)
PbS
Ag2S
CdS
Fe3O4
CoFe2O4
MnFe2O4
BaTiO3
LaF3
NaYF4
140oC and 200oC, SeO3- as Se
sources)
Zn:Se ≈51:49 when Se powder
was adopted as Se sources and
temperature was kept above
140oC.
Pb:S =53:47 for Fig 1B, and
about 1:1 for 2 samples obtained
at temperatures of 90 and 60oC
Ag:S =68:32 (taken from Fig 1B
and other 2 samples obtained at a
temperature conditions of 90oC
and 180oC, respectively)
Cd:S=53.1:46.9 (taken from 3
samples obtained at temperatures
of 50, 100 and 180oC,
respectively)
The ratio of Fe and O cannot be
determined by EDS, due to the
limitation of EDS. Elemental
analysis on the samples of Fig
1C show Fe:O= 43.1 :56.9
Co:Fe=32.5:67.5 (taken from
Fig 1C and other 2 samples
obtained at a temperature
conditions of 90oC and 120oC,
respectively)
Mn:Fe=31.2:68.8 (taken from
3 samples obtained at a
temperature conditions of 90oC,
120 and 180 oC respectively)
Ba:Ti=49.1:50.9 (taken from Fig
1C and other 2 samples obtained
at a temperature conditions of
160oC and 200oC, respectively)
The ratio of La and F cannot be
determined by EDS, due to the
limitation of EDS. Elemental
analysis on the samples of Fig
1D show La:F=24.3 :75.7
The existence of Na and Y can
be detected, however, due to its
smaller atomic weight, Na
cannot be analyzed accurately.
Hitachi H-800 TEM (Uncertainty =3~
5%)
Hitachi H-800 TEM (Uncertainty =3~
5%)
Hitachi H-800 TEM (Uncertainty =3~
5%)
Hitachi H-800 TEM (Uncertainty =3~
5%)
Element analysis
JEOL
JEM-2010F
HRTEM;
(Uncertainty=1~2%); Hitachi H-800
TEM (Uncertainty =3~5%)
Hitachi H-800 TEM (Uncertainty =3~
5%)
Hitachi H-800 TEM (Uncertainty =3~
5%)
Hitachi H-800 TEM (Uncertainty =3~
5%)
Element analysis
XRD structural analysis
Element analysis
Element
analysis
show
Na:Y:F=16.7: 17.2: 66.1
YF3
The amount of F cannot be
determined by means of EDS.
Nevertheless, the existence of Y
can be clearly detected.
YbF3
The amount of F cannot be
determined by means of EDS.
Nevertheless, the existence of
Yb can be clearly detected.
Ca10(PO4)6( Ca:P=63.2: 36.8 (taken from Fig
OH)2
1E (140oC)and other 3 samples
obtained at a temperature
conditions of 90, 120 and 180oC,
respectively)
XRD structural analysis
XRD structural analysis
Hitachi H-800 TEM (Uncertainty =3~
5%)
S Fig.19 EDS spectra were taken from Fig 1C Fe3O4, showing the existence of Fe.
Element report
Element kRation
--ZAF--
Weight% -Atom%-
Mn
0.30854
1.0000
30.8537
31.2034
Fe
0.69146
1.0000
69.1463
68.7966
S Fig.20 EDS spectra were taken from MnFe2O4 nanocrystals obtained at a
temperature of 90oC (Mn2+:Fe2+=1:2 (mole ratio)), showing the existence of Fe and
Mn. Quantitative analysis show that the Mn:Fe=31.2:68.8;
Element report
Element kRation
--ZAF--
Weight% -Atom%-
Co
0.33709
1.0000
33.7089
32.5132
Fe
0.66291
1.0000
66.2911
67.4868
S Fig.21 EDS spectra were taken from Fig 1C CoFe2O4, showing the existence of Fe
and Co. Quantitative analysis show that the Co:Fe=32.5:67.5;
Element report
Element kRation
--ZAF--
Weight% -Atom%-
Ti
0.25170
1.0000
25.1700
49.0945
Ba
0.74830
1.0000
74.8300
50.9055
S Fig 22. EDS spectra were taken from Fig 1C BaTiO3, showing the existence of Ba
and Ti. Quantitative analysis show that the Ba:Ti=49.1:50.9;
Element report
Element kRation
--ZAF--
Weight% -Atom%-
P
0.310711 1.0000
31.0711
36.7735
Ca
0.689289 1.0000
68.9289
63.2265
EDS spectra were taken from Fig 1E Ca10(PO4)6(OH)2, showing the
existence of P and Ca. Quantitative analysis show that the Ba:Ti=49.1:50.9;
S Fig 23.
S Fig24. EDS spectra were taken from Fig 1C TiO2, showing the existence of Ti.
Element kRation
--ZAF--
Weight% -Atom%-
Zn
0.43250
1.0000
43.2503
47.9320
Se
0.56750
1.0000
56.7497
52.0680
S Fig25.. EDS spectra were taken from Fig 1B ZnSe, showing the existence of Zn and Se.
Quantitative analysis shows that Zn:Se=47.9:52.1
Element kRation
--ZAF--
Weight% -Atom%-
Se
0.422085 1.0000
42.2085
50.9763
Cd
0.577915 1.0000
57.7915
49.0237
S Fig26. EDS spectra were taken from Fig 1B CdSe, showing the existence of Cd and
Se. Quantitative analysis shows that Cd:Se=49.0:51.0
Element kRation
--ZAF--
Weight% -Atom%-
S
0.201016 1.0000
20.1016
46.8581
Cd
0.798984 1.0000
79.8984
53.1419
S Fig27. EDS spectra were taken from CdS nanocrystals obtained at a temperature of
120oC, showing the existence of Cd and S. Quantitative analysis shows that
Cd:S=53.1:46.9
Element kRation
--ZAF--
Weight% -Atom%-
S
0.120371 1.0000
12.0371
46.9196
Pb
0.879629 1.0000
87.9629
53.0804
S Fig 28. EDS spectra were taken from Fig 1B PbS nanocrystals, showing the
existence of Pb and S. Quantitative analysis shows that Pb:S=53.1:46.9
Element kRation
--ZAF--
Weight% -Atom%-
S
0.122356 1.0000
12.2356
31.9239
Ag
0.877644 1.0000
87.7644
68.0761
S Fig 29. EDS spectra were taken from Fig 1B Ag2S nanocrystals, showing the
existence of Ag and S. Quantitative analysis shows that Ag:S=68.1:31.9
S Fig 30. EDS spectra were taken from the Fig 1A Ag nanocrystals, showing that
there only contains silver element.
Element kRation
--ZAF--
Weight% -Atom%-
Rh
0.0000
100.0000 100.0000
1.00000
S Fig 31. EDS spectra were taken from the Fig 1A Rh nanocrystals, showing that
there only contains Rh element.
Element kRation
--ZAF--
Weight% -Atom%-
Au
0.0000
100.0000 100.0000
1.00000
S Fig. 32. EDS spectra were taken from the Fig 1A Au nanocrystals, showing that
there only contains Au element.
Element kRation
--ZAF--
Weight% -Atom%-
Ir
0.0000
100.0000 100.0000
1.00000
S Fig 33. EDS spectra were taken from the Fig 1A Ir nanocrystals, showing that there
only contains Ir element.
S Fig 34. EDS spectra were taken from the Fig 1D YF3 nanocrystals, showing the
existence of Y element.
S Fig 35. EDS spectra were taken from the Fig 1D LaF3 nanocrystals, showing the
existence of La element.
S Fig 36. EDS spectra were taken from the Fig 1D YbF3 nanocrystals, showing the
existence of Yb element.
S Fig 37. EDS spectra were taken from the Fig 1D NaYF4 nanocrystals, showing the
existence of Y and Na elements.
Part III
Detailed experimental conditions for distinct class of nanocrystals with certain
composition and sizes
Supplementary Table 2
Table of the temperature range for the preparation of distinct class of nanocrystals:
(the optimal concentration conditions are in the range of 0.03~0.12mol/l-)
Class
Nanocrystals
Ag
Noble Metal
Nanocrystals
Ru, Rh and Ir
Au, Pd and Pt
Magnetic
MFe2O4
Fe3O4; MnFe2O4;
MgFe2O4;
ZnFe2O4;
CoFe2O4;
CuFe2O4; etc
Optimal
Temperature
Conditions(oC)
Temperature conditions
for specific sizes
90 (~6nm), 120(~10nm),
180 (~12nm)
90(~2nm), 120(~3nm),
20 ~ 200
180 (~4nm)
Au: 30 (~4nm),
60(6nm);
20 ~100
Pd, Pt: 50 (~2nm),
80(~4nm)
Fe3O4, CoFe2O4,
ZnFe2O4
90~200
120 (~6nm), 180 (11nm)
90~120(CuFe2O4)
MgFe2O4, MnFe2O4
120(~4nm), 180(~9nm)
80~120
140~200
(concentration of
NaOH,
5~10mol/l)
Dielectric
MTiO3
BaTiO3; PbTiO3;
SrTiO3; etc
Rare Earth
Fluorides
NaYF4; YF3; LaF3;
PrF3;
YbF3; etc
100~200
Sulfide: CdS; ZnS;
PbS; Ag2S; MnS,
CuS, etc
20~200
Selenide: ZnSe,
CdSe, MnSe;
PbSe, etc
Se powder as Se
sources: 140~200
Semiconductors
180(~17nm);
200(~20nm)
NaYF4, LaF3: 100
(~6nm), 180(~10nm);
PrF3: 180(~13nm);
YbF3:180 (~9nm);
Ag2S: 20 (~5nm)
90 (~7nm), 180
(~14nm);
PbS, ZnS: 90 (~4nm),
120 (5nm), 180 (6nm);
CdSe: 180 (~7nm), 140
(~5nm);
ZnSe: 180(~8nm),
140(~6nm)
Other New Type
Categories
Selenide: ZnSe,
CdSe, MnSe;
PbSe, etc
NaSeO3 as
sources: 120~200
Oxide: TiO2;
SnO2; CuO; ZnO;
ZrO2, etc
100~200
Ca10(PO4)6(OH)2;
CaCO3; BaSO4,
etc
Metal
Phthalocyanine;
Porphyrin;
Conducting
Polymer
100~200
140~200
CdSe: 180 (~7nm), 140
(~5nm);
ZnSe: 180(~8nm),
140(~6nm)
PbSe 180 (11 nm)
TiO2: 120 (3nm),
180(~4nm); ZrO2: 180
(~4nm); SnO2
180(~3nm); CuO: 180
(short nanorods with
diameters~10nm and
length 15~20nm)
Ca10(PO4)6(OH)2: 100 (9
×100~150nm), 180 (12
×180~200nm)
No apparent changes in
sizes were observed with
temperatures.
Concentrations, temperature are the main influential factors of this LSS strategy. To
get nearly monodisperse nanocrystals, optimal concentration conditions of
corresponding metal ions are usually kept in the range of 0.03~0.12mol/l-.
Concentrations lower than 0.03 mol/l- suffer from low efficiency in production, and
concentration higher than 0.12mol/l- may lead to the polydisperse nanocrystals.
Although all the nanocrystals are obtained based on the described LSS strategy, the
temperature conditions are quite different to ensure the chemical reactions to occur at
the interfaces.
(1) Noble metal nanocrystals
For the synthesis of noble metal nanocrystals, the re-dox reactions between different
noble metals ions and ethanol occur at quite different temperature conditions. In order
to get nearly monodisperse nanocrystals with high yields, temperatures should be kept
at 20~100oC for Au, Pd and Pt, while temperatures higher than 100 oC will lead to
aggregation of the nanocrystals. For the synthesis of Ru, Rh and Ir, a wider
temperature range of from 20~200oC can be adopted, and the sizes distributions are
not apparently influenced by temperature. The complete reduction of Ag ions occur at
a temperature above 80oC, Ag nanocrystals could be readily prepared in the
temperature range of 80~200oC, but when temperatures were controlled above 140 oC,
samples with wider size distributions were obtained while the average diameters
increase to 12nm. In order to get nanocrystals with sd<5%, the temperature should be
controlled in the range of 80~120oC. However in case of stearic acid and sodium
stearate, nearly monodisperse nanocrystals could be obtained at a temperature of
180oC.
35
percentage (%)
30
25
20
15
10
5
0
5.0
5.5
6.0
6.5
7.0
7.5
8.0
diameter (nm)
S Fig 38. Ag nanocrystals (90oC) 6.1±0.3 nm; sd =4.9%
0.40
0.35
Percentage
0.30
0.25
0.20
0.15
0.10
0.05
0.00
5
6
7
8
9 10 11 12 13 14 15 16 17
diameter (nm)
S Fig 39. 12 nm Ag nanocrystals (180oC) ,11.8
± 1.7nm; sd 14.4%)
0.5
Percentage
0.4
0.3
0.2
0.1
0.0
6.0
6.5
7.0
7.5
8.0
diameter (nm)
S Fig 40. Ag nanocrystals by adopting stearic acid and sodium stearate (180 oC) with
diameters 6.2 ± 0.4 nm; sd=6.4%;
(2) Sulfide nanocrystals
Since the direct reaction between the metal and sulfide ions can occur at a wide
temperature range, our reaction can be controlled at a temperature range of from room
temperature to 200oC. and as a result, the diameters can be rationally tuned. And the
following hydrothermal treatment or aging process will ensure monodispersity and
high crystalline of the nanocrystals. In our approach the diameter was mainly
determined by the reaction temperature, and an elongated time above 10 hours does
not have apparent effect on the diameters and a treatment time of less than 5hours
may result in polydisperse nanocrystals. For example, by altering the reaction
temperature from 90 to 180oC, the diameters of the as-obtained Ag2S nanocrystals can
be rationally tuned from about 7nm to about 14nm.
S Fig 41. Ag2S nanocrystals 7.3±0.4nm (90 oC)
(180 oC)
Ag2S nanocrystals 14.0±0.7nm
(3) Selenide semiconductors
When NaSeO3 was adopted as Se sources, the temperature should be kept above
120oC to get pure phase of selenide; When Se powder was adopted as Se sources, the
temperature should be kept above 140oC, and a temperature lower than 140oC will
lead to a mixed phase of Se and Selenide.
(4) Ferrite nanocrystals
At a temperature range of from room temperature to 200oC, pure phase ferrite can be
obtained. But in order to get nanocrystals with narrow size distributions, temperature
should be kept in the range of 90~200. For the synthesis of CuFe2O4, a temperature
higher than 120oC will lead to the generation of metal Cu in the final products.
(5) Titanate nanocrystals
Temperatures lower than 140oC would lead to a mixed phase of TiO2 and titanate.
Part IV
Nanocrystals obtained by employing different solvents instead of ethanol
In order to investigate the generality of this LSS strategy, we have adopted equal
amounts of solvents like glycol and n-octanol to replace ethanol, which will form the
liquid, solid and solution phase following the LSS strategy once mixed together with
aqueous solution, linoleic acid and Sodium linoleate. Part of our experimental results
show that the chemical reactions at the interface of the different phases can be tuned
in a way like ethanol-involved system. Here we show the samples of PbSe, CdSe,
ZnSe nanocrystals obtained from n-octanol-involved system, and CdSe nanocrystals
obtained from glycol-involved systems. More studies are still in progress now.
S Fig. 42. TEM images of CdSe (a, b, Cd2+ : SeO32- = 1:1; 160oC) and ZnSe
nanocrystals(c) obtained from n-octanol-involved system (Zn2+ : SeO32- = 1:1;
160oC )
S Fig. 43. TEM images of PbSe (Pb2+ : SeO32- = 1:1; 160oC) obtained from
n-octanol-involved system
S Fig. 44. TEM images of CdSe (Cd2+ : SeO32- = 1:1; 160oC) obtained from
glycol-involved systems
Part V
Magnetic characterization of MFe2O4 (M=Fe, Co, Mn, Mg, Zn) nanocrystals;
Uv-vis spectra of Ag nanocrystals with different sizes; Visible-to-naked-eyes
green upconversion emissions from NaYF4 nanocrystals
S Fig 45. Hysteresis loops of the 1. MgFe2O4 2. Fe3O4 3. MnFe2O4 4. ZnFe2O4
nanocrystals; As a result of the alterations of compositions, the magnetic properties of
the MFe2O4 nanocrystals changes correspondingly.
S Fig 46. Hysteresis loops of the CoFe2O4 nanocrystals
Magnetic measurements on all the Fe3O4, MnFe2O4, MgFe2O4 and ZnFe2O4
indicate that the particles are superparamagnetic at room temperature, meaning that
the thermal energy can overcome the anisotropy energy barrier of a single particle,
and the net magnetization of the particles in the absence of external field is zero.
There is no hysteresis loop for the Fe3O4, MnFe2O4, MgFe2O4 and ZnFe2O4
nanocrystals. Under a large external field, the magnetization of the particles aligns
with the field direction and reaches its saturation value. For Fe3O4 nanocrystals with
diameters ~7 nm the Saturation Magnetization value is about 45 emu/g, lower than the
commercial available Fe3O4 powders, most likely due to the surface spin canting of
the small magnetic nanoparticles. As a result of the alteration of the compositions, the
Saturation Magnetization values change correspondingly, indicating the incorporation
of different metal ions into the Fe-O matrix. While for the CoFe2O4 nanocrystals, ,
there is a hysterisis loop and the covercity of the CoFe2O4 nanocrystals is about
250Oe at 300K, compared with the 0Oe of Fe3O4, indicating that the incorporation of
the Co cation in the Fe-O matrix increases the magnetic anisotropy of the materials.
(2) Uv-vis absorption spectra of Ag nanoparticles with different sizes
S Fig 47. Uv-vis absorption spectra of Ag nanoparticles with different sizes
S Fig 48. Room temperature self-assembly of the monodisperse Ag nanocrystals
(6nm) on silicon substrate;
(3) Visible-to-naked-eyes Green Upconversion Emissions from the Fluorescent
Fluoride nanocrystals
S Fig 49. TEM, Visible-to-naked-eyes Green Upconversion Emissions and spectra of
Yb/Er co-doped NaYF4 nanocrystals, excited with a 980nm laser.
Part VI Synthesis and characterization of New-type Nanocrystals
1. Organic optoelectronic semiconductors: Metal Phthalocyanine nanocrystals
Phthalocyanine (Pcs) is a typical optoelectronic semiconductor compound, which
shows excellent optoelectronic properties as well as good chemical and physical
properties. The big planar -conjugated system made Pcs excellent electron donating
chromophores and high charge-carrier mobility organic semiconductors (p-type) with
characteristic electronic absorption from the ultraviolet to visible region. And most
importantly, Pcs can complex with nearly all the metal ions to form metal Pcs and as a
result, the optoelectronic, chemical and physical properties can be rationally tuned.
Based on the LSS strategy, different metal Phthalocyanine monodisperse nanocrystals
could be obtained.
Chemicals: metal salts (acetate or chloride), o-dicyanobenzene, n-pentanol,
linoleic acid, Sodium linoleate, ethanol and distilled water.
The synthesis was carried out based on the described LSS strategy. In a typical
synthesis, 15ml aqueous solution containing metal salts (for example, 0.1g CuCl2 and
other soluble chlorides), 1.6g Sodium linoleate, 10ml ethanol and 2ml linoleic acid
were added into 40 ml autolcave under agitation to form a ternary system of liquid
(organic phase of o-dicyanobenzene, n-pentanol, ethanol and linoleic acid), solid
(metal linoleate) and solution (aqueous phase of metal salts), then the system were
sealed and treated in a temperature range of 140~200oC. Under the adopted
temperature conditions, the o-dicyanobenzene will polymerize into Pcs, which then
complex with the metal ions from the metal linoleate solid phase to form various
metal Pcs. When the nanorystals reach certain sizes, the nanocrystals will be separated
from the bulky solution phase and collected in forms of solid powders.
Fig. S10 show the TEM images of the Cu-Pcs nanoparticles with diameters ~0.6nm.
Electron Energy Loss Spectra were taken from the as-obtained nanoparticles, and
proved the existence of N element in the products.
By adopting different metal salts, various metal Pcs can be obtained with tunable
optoelectronic properties. As a new-type organic optoelectronic semiconductor
nanocrystals, monodisperse metal Pcs nanoparticles may provide as a model system in
the investigation of nano/size effect in this fields and/or as building blocks in the
fabrication of organic optoelectronic semiconductor-based nanodevices.
S Fig 50. Structure of Metal Pcs; TEM images of Cu-Pcs nanoparticles
S Fig. 51 Carbon K-edge of the EELS spectra
The initial peak in the carbon K-edge spectrum (~286.3 eV) is due to 1s-π*
transitions (C=C), which reveals the C sp2 hybridization state in CuPc nanoparticles.
The presence of C–N bonds corresponds to the appearance of peak shoulder at energy
loss ~293 eV, which have dominantly σ* character (1s->σ* transition).
S Fig 52. N K-edge of the EELS spectra
The N-K edge suggests that N atoms in CuPc nanoparticles are sp2 hybridized (Fink, J.;
Scheerer, B.; Wernet, W.; Monkenbusch, M.; Wegner, G. Phys Rev B 1986, 34, 1101-1115). The
peak at ~403 eV could be assigned to 1s->π* transition and /or 1s->σ* transition.
S Fig 53 Electron Energy Loss Spectrum of Pcs nanoparticles, showing the
existence of N element in the nanocrystals.
S Fig 54. IR spectra of the as-obtained Cu Pc nanoparticles
The IR bands characteristic of metallophthalocyanine ring is a ring vibration at 1082
cm-1 (reported data: 1080 cm-1, see ref: Liu YQ, Zhu DB, Synthetic Metal, 1995, 71,
1853-1856). In the spectral region 1500-1400 cm-, the spectrum of Cu Pc
nanoparticles shows overlapped broadening bands at 1457 cm-1 and 1494cm-1, which
can be assigned as the fundamental vibration of pyrrole ring and C=C stretching
vibration of benzenoid groups, respectively. In the spectral region 1600-1500 cm-, the
spectrum of Cu Pc nanoparticles shows slightly-overlapped broadening bands at 1571
and 1606 cm-1, which can be assigned as C-C vibration of pyrrole (reported data:
1578 cm-1, see ref: Janczak J, Kubiak R, Polyhedron, 2002, 21, 265-274) and
benzenoid groups, respectively. The bands at 750 cm- can be assigned as the
out-of-plane bending mode of C-H in substituted benzene.
S Fig 55. Uv-vis spectra of Cu-Pc nanoparticles (in cyclohexane)
The as-obtained CuPc nanoparticles show characteristic Q (650nm) and B-band
(410nm) absorption of metal Phthalocyanine. However, the Q-band absorption at
650nm is comparatively weak and the B-band adsorption at 410nm is rather strong.
More detailed study is still needed to fully address this phenomenon. Nevertheless,
the Uv-vis spectra prove the formation of Cu-Pc nanoparticles.
2. Porphyrin nanocrystals
Metal Porphyrins, another kind of compounds possessing big planar -conjugated
system, are the important components of chlorophyll, animal liver and myoglobin etc.
Metal Porphyrin-based catalysis, biosimulation have been widely carried out. In a
similar way to that of the metal Phthalocyanine, metal Porphyrin cnanoparticles can
be prepared based on the LSS strategy.
In a typical synthesis, phenyl aldehyde (or substituted phenyl aldehyde) and pyrrole
as the primary raw materials were dissolved into propanoic acid, then 1.6g sodium
linoleate, 2ml linoleate, 16ml ethanol and 15ml aqueous solution containing 0.1g
CuCl2 (Metal ions: in case of Cu), were mixed together to form the three phase of
liquid, solution and solid. At the interfaces of different phases, the polymerization
reaction between the phenyl aldehyde (or substituted phenyl aldehyde) and pyrrole
result in Porphyrin, which will complex with the metal ions (from the solid phase of
metal linoleate) and form metal Porphyrin. The long alkyl chains covered on the
nanocrystals will ensure the separation of the nanocrystals from the solution.
Systematic studies on the nanoparticles of metal Porphyrin will bring great
opportunities in the research of biosimulation in nanoscale, nanomedicine and
catalysis, etc.
S Fig 56. Diagram for the synthesis of Porphyrin
S Fig 57. TEM images of Porphyrin nanoparticles
S Fig 58 IR spectra of copper porphyrin nanoparticles
The as-obtained copper porphyrin nanoparticles are examined with IR spectra. And all
the bands are assigned according to reference Porhpyrin handbook (Kadish KM,
Smith KM, Guilard R, the Porhpyrin Handbook, Volume2, 333-335; Academic press,
USA). Bands at 775-780, 843-850, 999-1013, 1064-1078, 1360-1362, 1390-1392,
1459-1483 cm- should mostly be due to the skeletal vibrations. Bands at 3060, 2916
and 2849cm- are signed to C-H, and those at 1572, 1512and 1463 cm- to C=C and
C=N.
S Fig59. Uv-vis spectra of Porphyrin nanoparticles
As expected, the UV-vis spectra of porphyrin nanoparticles show characteristic Q
(590 nm) and Soret-band (~510nm) absorption, which prove the formation of
porphyrin. (See ref, Gong XC, et al., J. Am. Chem. Soc., 2002, 124, 14290)
3. Biocompatible biomedical nanocrystals
Hydroxyapatite, Calcium carbonate, Barium sulfate, etc have important
applications in biomedical fields.
Hydroxyapatite (denoted as HAp), Ca10(PO4)6(OH)2 , a calcium phosphate salt, is
the mineral constituent of human hard tissues (bones, teeth, etc.) and is of importance
in the biomedical field as a raw material for the preparation of artificial bone graft. It
is also a promising material as reinforcing filler for composites, insulating agents and
chromatomedium for simple and rapid fractionation of proteins and nucleic acids. The
versatility of HAp makes it one of the most urgent tasks today to prepare
monodisperse biocompatible HAps nanocrystals.
Based on the reaction between Ca2+ and PO43-, uniform HAp nanorods could be
prepared.
Chemicals: Ca(NO3)2, Na3PO4, linoleic acid, Sodium linoleate, ethanol and
distilled water.
The synthesis was carried out based on the described LSS strategy. In a typical
synthesis, 15ml aqueous solution containing 1g Ca(NO3)2, 1.6g Sodium linoleate,
10ml ethanol and 2ml linoleic acid were added into 40 ml autolcave under agitation to
form a ternary system of liquid (linoleic acid and ethonal), solid (calcium linoleate)
and solution (aqueous phase of Ca(NO3)2), then the system were sealed and treated in
a temperature range of 120~200oC. The as-obtained precipitates are characterized to
be uniform nanorods of Ca10(PO4)6(OH)2, which self assemble into regular
two-dimensional arrays on the TEM grids due to the uniformity in shape and sizes.
Based on a similar process, uniform CaCO3 and BaSO4 nanocrystals could also be
obtained. We believe that other useful biomedical nanocrystals can be further
explored following this LSS strategy, which will contribute greatly to the
development of nanomedicine and biomedical materials areas.
S Fig 60. TEM images of Ca10(PO4)6(OH)2 nanocrystals
S Fig 61. XRD patterns of Ca10(PO4)6(OH)2 nanocrystals
4. Conducting polymer nanoparticles
The preparation of uniform quantum dots of semiconductors and/or metals have
enabled the progress in the understanding of quantum effects in the transport and/or
optical properties, based on which various nanodevices could be designed. However,
the general principle of space-confined transport properties of conducting polymer has
not been addressed because the lack of an ideal model system.
Uniform Conducting polymer nanoparticles such as PAn and PPy have been
obtained following this LSS strategy.
In a typical synthesis, aniline (or pyrrole) were dissolved into the mixture of
ethanol and linoleic acid, (NH4)S2O8 was dissolved into distilled water, then together
with the solid sodium linoleate, all the reagents were mixed to form the liquid, solid
and solution systems. Then the autoclave was treated at a temperature of 140~200oC.
PPy
PAn
S Fig 62 TEM images of PPy and PAn nanoparticles
S Fig 63. UV/Vis spectra of PAn nanoparticles
UV spectra present typical peaks centered at ~320 nm due to π-π* transition of
benzenoid groups and the peak at 500~640 nm due to the protonation of the imine
groups. (Stafstrom, S.; Breda, J. L.; Epstein, A. J.; Woo, H. S.; Tanner, D. B.; Huang,
W. S.; MacDiarmid, A. G. Phys Rev Lett 1987, 59, 1464-1467.)
.
S Fig 64. FTIR spectra of PAn nanoparticles
The fundamental C=C stretching vibration of benzenoid groups at 1494cm-1, C=C
stretching vibration of quinonoid groups at 1590 cm-1, the C-N stretching vibration of
QBtQ, QBcQ, QBB, BBQ and BBB at 1374 cm-1,1298 cm-1 and 1238 cm-1 (Q:
quinonoid groups; B: benzenoid groups; t: trans; c: cis), the N=Q=N stretching
vibration mode at 1140 cm-1 are all in good consistent with the FTIR spectra for PAn.
(A. Drelinkiewicz, M. Hasik, and M. Choczynski1, Mater. Res. Bull. 1998, 33,
739-762)
S Fig 65.
UV/Vis spectra of PPy nanoparticles
Corresponding spectra of PPy nanoparticles show π-π* transition peak of pyrrole
ring around ~340 nm. This absorption band could be attributed to the transitions
between valence band and antibipolaron band. (J. L. Bredas, J. C. Scott, K. Yakushi G.
B. Street, Phys. Rev. B 1984, 30, 1023-1025)
S Fig 66. FTIR spectra of PPy nanoparticles
The fundamental vibration of pyrrole ring at 1557 and 1457 cm-1, =C-H in-plane
vibration at 1290 and 1045 cm-1, C-N stretching vibration at 1199 cm-1, together with
C-H ring out-of-plane bending mode at 792 and 679 cm-1 are all in good consistent
with the FTIR spectra for PPy obtained via common method. (G. I. Mathis, V.-T.
Truong, Synth. Met. 1997, 89, 103-109.)