{200}. {220}. {311}{222}. (e) Pd cube. Intensity (a.u.). Intensity (a.u.). Intensity (a.u.). Intensity (a.u.). Intensity (a.u.). AgBr. AgBr. Au {111}. Au, Ag. {111}. Au {200}.
Supporting Information
Syntheses of Au@PdAg and Au@PdAg@Ag Core–Shell Nanorods through Distortion Induced Alloying between Pd Shells and Ag Atoms over Au Nanorods Masaharu Tsuji,*†,‡,§ Koichi Takemura,‡ Chihiro Shiraishi,‡ Koji Ikedo,‡ Keiko Uto,† Atsuhiko Yajima,§ Masashi Hattori,† Yukinori Nakashima,‡ Kento Fukutomi,‡ Kunihiko Tsuruda,§ Takeshi Daio,¶ Takeshi Tsuji,# and Satoshi Hata ‡
† Institute
for Materials Chemistry and Engineering, Kyushu University, Kasuga 816-8580, Japan
‡ Department
of Applied Science for Electronics and Materials, Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580, Japan
§ Department
of Automotive Science, Graduate School of Integrated Frontier Sciences, Kyushu University, Kasuga, 816-8580, Japan ¶ International
Research Center for Hydrogen Energy, Kyushu University, Motooka, Fukuoka 819-
0395, Japan # Department
of Material Science, Interdisciplinary Graduate School of Science and Engineering, Shimane University, Matsue, 690-8504, Japan S1
(a)
(b)
Fig. SI-1. TEM images of Au NRs. S2
(a) Traditional shape {100} {100} {110} {100}
(b) New shape {100} {110}
{111}
{250} or {5 12 0} {100}
{110}
{100}
{110} {250} or {5 12 0}
Fig. SI-2. Traditional and new crystal structures of Au NRs. S3
(a) Au@Pd nanorod
(b) Au@PdAg nanorod
(b) Au@PdAg@Ag nanorod
Ag Au
Pd
Pd‐Ag
Observation from ＜100＞ direction
Fig. SI-3. SAED patterns of cuboid Au@Pd, Au@PdAg, and Au@PdAg@Ag NRs. S4
(a) STEM
(b) AuPdAg component
(d) Pd component
(e) Ag component
(c) Au component
10 nm Fig. SI-4. HAADF-STEM and STEM-EDS images of cuboid Au@PdAg NRs. S5
(a) TEM
100 nm
Fig. SI-5. Expanded TEM image of cuboid Au@PdAg@Ag NRs prepared after heating for 30 min.
S6
(A) 1 h
(B) 14 h
(C) 48 h
(c) (a) TEM 100 nm
BF
100 nm
BF
(b) AuPdAg component
(c) Au component
(d) Pd component
(e) Ag component 50 nm Fig. SI-6. TEM and TEM-EDS images of cuboid Au@PdAg@Ag NRs prepared after heating for 1, 14, and 48 h at three-times-higher concentration of AgNO3 and two-times-higher concentration of ascorbic acid than S7 those in Figure 3. Scale bars represent 50 nm.
(a) TEM
(b) AuPdAg component
20 nm
BF
(e) Ag components
(f) Line analysis (a.u.)
(d) Pd component
(c) Au component
20 nm Fig. SI-7. (a) TEM and (b)-(e) TEM-EDS images and (f) line analysis along a blue line in (a) of cuboid Au@PdAg@Ag NR prepared after heating for 48 h at three-times-higher concentration of AgNO3 and twotimes-higher concentration of ascorbic acid than those in Figure 3. 19 S8
Intensity (a.u.) Intensity (a.u.) Intensity (a.u.) Intensity (a.u.) Intensity (a.u.)
400 Au {111}
300 200
(a) Au NRs
{200}
100
{220}
{311}
0 200
150
Au {200}
{222}
(b) Au@Pd NRs
Pd {200}
100 50
Au {111}
0 100 75 50
AgBr
(c) Au@PdAg NRs
Au, Ag {111}
25 0 500 375
Au, Ag {111}
(d) Au@PdAg@Ag NRs
250
{200}
125 AgBr 0 300 225
{220}
Pd {111}
150
(e) Pd cube
{200} {220}
75 0
30
{311} {222}
40
50
60
70
{311}
80
{222}
90
2 / deg Fig. SI-8. XRD patterns of (a) Au, and cuboid (b) Au@Pd, (c) Au@PdAg, and (d) Au@PdAg@Ag NRs, and (e) Pd cube. S9
(b) AuPd component
(a) STEM
(d) Pd component
(c) Au component
25 nm 25 nm Fig. SI-9. HAADF-STEM and STEM-EDS images of cuboid Au@Pd NRs. S10
Fig. SI-10. XRD patterns of (a) Au, and dumbbell (b) Au@Pd, (c) Au@PdAg, and (d) Au@PdAg@Ag NRs, and (e) Pd cube. S11
(b) AuPd component
(a) STEM
(d) Pd component
(c) Au component
25 25 nm nm Fig. SI-11. HAADF-STEM and STEM-EDS images of dumbbell Au@Pd NRs. S12
Pd shell Ａｕ core
2 nm Fig. SI-12. HAADF-STEM image of cuboid Au@Pd NR. S13
2 nm Fig. SI-13. HRTEM-image of cuboid Au@Pd NR. Red circles show dark contrast due to lattice distortion. S14
(a) STEM
(b) PdAg component
Ag
reduction
(c) Pd component
(d) Ag component
Pd
＋ Ag+
Pd nanocube
20 nm Fig. SI-14. HAADF-STEM and STEM-EDS images of Pd@Ag nanocubes prepared after heating for 10 min at 60 oC. S15
Pd
Pd@Ag
Intensity (a.u.)
300
(a) Pd cube
225 150
{200}
75 0
30
Intensity (a.u.)
Pd {111}
{220}
{311} {222}
40
50
100
60
70
AgBr
80
90
(b) Pd@Ag cube
75 50 25 0
30
Ag {111}
40
50
60
70
80
2 / deg Fig. SI-15. XRD patterns of (a) Pd cubes and (b) Pd@Ag cubes. S16
90
Extinction
0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0
Extinction
0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0
(a) Au nanorod Au@Pd (rectangular)
400
600 800 1000 Wavelength / nm
1200
(b) Au nanorod Au@Pd (dumbbell)
400
600 800 1000 Wavelength / nm
1200
Fig. SI-16. UV-Vis-NIR spectra of (a) Au and cuboid Au@Pd NRs and (b) Au and dumbbell Au@Pd NRs. S17
Table SI-1. Observed 2 values in each particle in XRD patterns Pd or Au component of nanoparticles
2 / deg (111)
(200)
(220)
fcc Pd (standard data)
40.12
46.66
68.09
Pd in Au@Pd (cuboid)
39.84
46.22
67.98
Pd in Au@PdAg (cuboid)
39.80
46.06
67.86
Pd in Au@PdAg@Ag (cuboid)
39.84
45.98
67.92
Pd in Au@Pd (dumbbell)
39.56
45.78
67.58
Pd in Au@PdAg (dumbbell)
39.56
45.62
67.42
fcc Au (standard data)
38.19
44.38
64.58
Au in Au@Pd (cuboid)
38.58
44.04
64.96
Au in Au@Pd (dumbbell)
38.36
44.12
65.30
S18
