Facile Synthesis of Cu2O Nanocrystals with Systematic Shape ...
Supporting Information
Facile Synthesis of Cu2O Nanocrystals with Systematic Shape Evolution from Cubic to Octahedral Structures Chun-Hong Kuo and Michael H. Huang* Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
Figure S1. Size distribution histograms of Cu2O nanocrystals synthesized in sample bottles A–D with (A) truncated cubic, (B) cuboctahedral, (C) truncated octahedral, and (D) octahedral structures. Average particle sizes are also given. 1
Figure S2.
A photograph of the four solutions showing slight color variation from
purplish red for sample A to yellow for sample D.
The solutions were prepared with
the addition of 0.25 mL of 1 M NaOH.
Figure S3. (a) SEM image of small Cu2O nanoparticles adsorbing onto the rough surface of a developing truncated octahedral nanocrystal.
This image was obtained
by observing nanoparticles formed in sample bottle C after just 5 min of reaction.
(b)
SEM image of an aggregate of small Cu2O nanoparticles next to some octahedral nanocrystals.
This image was obtained from sample bottle D after 5 min of reaction.
The aggregate is likely to develop into an octahedral nanocrystal.
2
Figure S4. SEM images of the Cu2O nanoparticles made following the preparation procedure described in the Experimental Section, but with the capping surfactant replaced with CTAB.
Systematic shape evolution of structurally well-defined Cu2O
nanocrystals cannot be achieved.
Scale bars in all insets are equal to 100 nm.
3
Figure S5. Size distribution histograms of the Cu2O nanocrystals synthesized by adding 0.75 mL of 0.1 M NaOH to the solutions in sample bottles A–D.
The average
particle sizes are (A) 532 ± 75, (B) 565 ± 65, (C) 467 ± 49, and (D) 429 ± 49 nm.
4
Truncated Cubes Calculated Particle
Volume of NaOH
pH Value
0.250 mL
12.05
296 ± 39 nm
13 %
0.375 mL
12.42
429 ± 58 nm
14 %
0.500 mL
12.55
439 ± 44 nm
10 %
0.625 mL
12.66
516 ± 59 nm
11 %
0.750 mL
12.77
532 ± 75 nm
14 %
Size
Standard Deviation
Cuboctahedra Calculated Particle
Volume of NaOH
pH Value
0.250 mL
11.68
382 ± 27 nm
7%
0.375 mL
11.94
546 ± 71 nm
13 %
0.500 mL
12.10
549 ± 58 nm
11 %
0.625 mL
12.17
573 ± 84 nm
15 %
0.750 mL
12.36
565 ± 65 nm
12 %
Size
Standard Deviation
Truncated Octahedra Calculated Particle
Volume of NaOH
pH Value
0.250 mL
11.44
218 ± 25 nm
11 %
0.375 mL
11.85
451 ± 57 nm
13 %
0.500 mL
11.99
455 ± 38 nm
8%
0.625 mL
12.11
482 ± 71 nm
15 %
0.750 mL
12.39
467 ± 49 nm
10 %
Size
Standard Deviation
Octahedra Calculated Particle
Volume of NaOH
pH Value
0.250 mL
11.34
162 ± 20 nm
12 %
0.375 mL
11.75
362 ± 45 nm
12 %
0.500 mL
11.91
406 ± 35 nm
9%
0.625 mL
12.00
456 ± 63 nm
14 %
0.750 mL
12.11
429 ± 49 nm
11 %
Size
Standard Deviation
Table S1. Average sizes and standard deviations of the Cu2O nanocrystals synthesized in sample bottles A–D and the solution pH values by adding different amounts of NaOH to the solutions. 5
Figure S6. Graphical presentation of the data shown in Table S1.
6
Figure S7. UV–vis absorption spectra of the larger Cu2O nanocrystals made in samples A–D with the addition of 0.75 mL of 1.0 M NaOH.
The intrinsic light
absorption band of these Cu2O nanocrystals at ~470 nm for samples A, C, and D and at 490 nm for sample B can be clearly distinguished from the light scattering bands. This is because at these particle sizes (that is, 430–570 nm), the continuous light scattering bands are more widely separated from the intrinsic absorption band of the nanocrystals.
The absorption peak maximum at 554 nm for Rhodamine B fits right
in the depression region between the intrinsic absorption band and the light scattering bands of the Cu2O nanocrystals for all the samples.
Thus, these nanocrystals were
chosen for the photodecomposition study of Rhodamine B to minimize the effect of strong absorption from the light scattering bands. B solution was 2.5 mg/L.
7
The concentration of Rhodamine
Facile Synthesis of Cu2O Nanocrystals with Systematic Shape Evolution from Cubic to Octahedral Structures Chun-Hong Kuo and Michael H. Huang* Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
Figure S1. Size distribution histograms of Cu2O nanocrystals synthesized in sample bottles A–D with (A) truncated cubic, (B) cuboctahedral, (C) truncated octahedral, and (D) octahedral structures. Average particle sizes are also given. 1
Figure S2.
A photograph of the four solutions showing slight color variation from
purplish red for sample A to yellow for sample D.
The solutions were prepared with
the addition of 0.25 mL of 1 M NaOH.
Figure S3. (a) SEM image of small Cu2O nanoparticles adsorbing onto the rough surface of a developing truncated octahedral nanocrystal.
This image was obtained
by observing nanoparticles formed in sample bottle C after just 5 min of reaction.
(b)
SEM image of an aggregate of small Cu2O nanoparticles next to some octahedral nanocrystals.
This image was obtained from sample bottle D after 5 min of reaction.
The aggregate is likely to develop into an octahedral nanocrystal.
2
Figure S4. SEM images of the Cu2O nanoparticles made following the preparation procedure described in the Experimental Section, but with the capping surfactant replaced with CTAB.
Systematic shape evolution of structurally well-defined Cu2O
nanocrystals cannot be achieved.
Scale bars in all insets are equal to 100 nm.
3
Figure S5. Size distribution histograms of the Cu2O nanocrystals synthesized by adding 0.75 mL of 0.1 M NaOH to the solutions in sample bottles A–D.
The average
particle sizes are (A) 532 ± 75, (B) 565 ± 65, (C) 467 ± 49, and (D) 429 ± 49 nm.
4
Truncated Cubes Calculated Particle
Volume of NaOH
pH Value
0.250 mL
12.05
296 ± 39 nm
13 %
0.375 mL
12.42
429 ± 58 nm
14 %
0.500 mL
12.55
439 ± 44 nm
10 %
0.625 mL
12.66
516 ± 59 nm
11 %
0.750 mL
12.77
532 ± 75 nm
14 %
Size
Standard Deviation
Cuboctahedra Calculated Particle
Volume of NaOH
pH Value
0.250 mL
11.68
382 ± 27 nm
7%
0.375 mL
11.94
546 ± 71 nm
13 %
0.500 mL
12.10
549 ± 58 nm
11 %
0.625 mL
12.17
573 ± 84 nm
15 %
0.750 mL
12.36
565 ± 65 nm
12 %
Size
Standard Deviation
Truncated Octahedra Calculated Particle
Volume of NaOH
pH Value
0.250 mL
11.44
218 ± 25 nm
11 %
0.375 mL
11.85
451 ± 57 nm
13 %
0.500 mL
11.99
455 ± 38 nm
8%
0.625 mL
12.11
482 ± 71 nm
15 %
0.750 mL
12.39
467 ± 49 nm
10 %
Size
Standard Deviation
Octahedra Calculated Particle
Volume of NaOH
pH Value
0.250 mL
11.34
162 ± 20 nm
12 %
0.375 mL
11.75
362 ± 45 nm
12 %
0.500 mL
11.91
406 ± 35 nm
9%
0.625 mL
12.00
456 ± 63 nm
14 %
0.750 mL
12.11
429 ± 49 nm
11 %
Size
Standard Deviation
Table S1. Average sizes and standard deviations of the Cu2O nanocrystals synthesized in sample bottles A–D and the solution pH values by adding different amounts of NaOH to the solutions. 5
Figure S6. Graphical presentation of the data shown in Table S1.
6
Figure S7. UV–vis absorption spectra of the larger Cu2O nanocrystals made in samples A–D with the addition of 0.75 mL of 1.0 M NaOH.
The intrinsic light
absorption band of these Cu2O nanocrystals at ~470 nm for samples A, C, and D and at 490 nm for sample B can be clearly distinguished from the light scattering bands. This is because at these particle sizes (that is, 430–570 nm), the continuous light scattering bands are more widely separated from the intrinsic absorption band of the nanocrystals.
The absorption peak maximum at 554 nm for Rhodamine B fits right
in the depression region between the intrinsic absorption band and the light scattering bands of the Cu2O nanocrystals for all the samples.
Thus, these nanocrystals were
chosen for the photodecomposition study of Rhodamine B to minimize the effect of strong absorption from the light scattering bands. B solution was 2.5 mg/L.
7
The concentration of Rhodamine
