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Studies on the Syntheses and Applications of 3D Arrayed Quantum-Dot Nano-Clusters
with the Orders of Terasin Zeolite Hosts
경북대학교 응용화학과 구조화학연구실E1-301~303, Tel. 82-(0)53-950-5589, Fax. 82-(0)53-950-6594
Nam Ho Heo, Professor, Ph.D. ([email protected])Ph.D. Candidates Seok Han Kim, Gee Jin Jung, Ghyung Hwa Kim
Master Candidates Hyun Jung Kim, Thanh Nga Nguyen Thi, Cheol Woong Kim
Subjects & Objectives Studies onA. The Nature of Various Zeolitic Species
a. New Chemical Speciesb. New Sorption Complexesc. Advanced Materials
(3D Nanoclusters etc)d. Knowledge on Various Known Species
B. The Applications of Zeolitesa. Sorption Propertiesb. Encapsulation & Occlusionc. Physical Properties of New Materialsd. Others
Methodology
A. Syntheses & Modificationsa. Synthesesb. Static & Dynamic Ion-Exchangesc. Chemical & Physical Modificationsd. Sorption & Reactions
B. Characterizationsa. Crystallographic Studiesb. Spectroscopic Propertiesc. Sorption Propertiesd. Others
Prepare SingleCrystals
X-ray Experime
nt
Structure Determinati
on
Chracterization of New Nano Mater
ials
Advanced Nano Materials
A. Quantum Dots (Nanoclusters) a. Nanoclusters of Indium Speices
1. In5 Clusters in In-Aa-c 2. In5 Clusters in In-Xd
b. Nanoclusters of Silver Halides 1. Ag4I4 Clusters in K-Ae
2. Ag4Br4 Clusters in K-Af
B. 3D Array of Quantum Dots a. 3D In5 Clusters in In-Xg
aN. H. Heo et al, J. Phys. Chem. B 1997, 101, 5531-5539. bN. H. Heo et al, J. Phys. Chem. B 1998, 102, 17-23.cN. H. Heo et al, J. Phys. Chem. B 2002, 106, 4578-4587. dN. H. Heo et al, J. Phys. Chem. B 2000, 104, 8372-8381. eN. H. Heo et al, J. Phys. Chem. B 2004, 108, 3168-3173. fN. H. Heo et al, manuscript in preparation.gN. H. Heo et al, J. Phys. Chem. B 2003, 107, 1120-1128.
SynthesisSynthesisSynthesisSynthesis
* Y. Kim, K. Seff, J. Phys. Chem., 82, 1978, 1071
CharacterizationCharacterization
Na-A
By flow method for 2 days
Ag-A*
0.05M aqueous AgNO3 solution
Washing with MeOH
CAD4/Turbo DiffractometerPAL X-ray DiffractometerRIST XPS, etc
In5 Nanoclusters in In-A & X
All sodalite units of In66-X are filled with the
In5 clusters
All sodalite units of In66-X are filled with the
In5 clusters
XPS(ESCA) Experiment
Electron-Probe X-rayAnalysis
Ag4I4 Nanoclusters in K-A(Ag4I4)0.5(KI)
In(U)
In(I’)
109.47o
2.6831(13) Å
In(U)
In(I’)
109.47o
2.6831(13) Å
In(I’) - O(3) = 2.170(7) Åe
In2+ = 0.85 ~ 1.05 Å
(In0 = 1.63 Å, In
+ = 1.25 Å, O- = 1.32 Å)
Diameter of AgI nanocluster= 4.80 + 1.13 + 1.96= 7.89 Å
One of the smallest nanoclusters in the world
400 420 440 460 480 500 520 540 560 580 600
Abs
orba
nce
Wavelength (nm)
AgI K-A(0.5Ag
4I4)(KI)
Ag-A K-A
400 420 440 460 480 500 520 540 560 580 600
0
Wavelength (nm)
AgI K-A(0.5Ag
4I4)(KI)
Blue shift
Evidence for Quantum Size Effect of Ag4I4
Nanoclusters(UV-Vis Spectrum)
Applications of Ag4X4 & Inx Nanoclusters
- Photocatalysts for solar energy conversion.e
- Image plates for x-ray computerized radiography.f - Medium for optical information or image storage. G
- Semiconductor materials for new device.
e R. Beer, G. Calzaferri, J. lin, and B. Waldeck, Coord. Chem. Rev 111, 1991, 193
f Sonada, M.; Takano, M.; Miyahara, J.; Kato, H. Radiology 148, 1983, 833 g Hirono, T.; Yamada, T. Japanese Patent 61-061894, 1986
K-A(AgI or AgBr )
Reaction with KI (or KBr) solution in MeOH for 2 days
1000 800 600 400 200 00
20000
40000
60000
80000
100000
120000
140000
160000
180000
200000
In 4
d
Al 2
pSi
2p
Al 2
s + T
l 4f
Si 2
s
Na K
LLTl 4
d5Tl
4d5
In 3
d5In
3d3
In 3
p1
O 1s
In 3
p3
O KL
L
In M
NN
Na 1
s ESCA Survey #6_Na-X #7_Tl-X #8_In-X
N(E)
/E
Binding Energy, eV
X-ray Photoelectron Spectroscopy (XPS)
XPS Image of In-X
VG XPSLAB 250
0 1 2 3 4 5
L's
L's
L'sIn
Tl Ma's & M's
Si Ka's
Al K's
In87-X
In88-X
Tl92-X
Rela
tive I
nte
nsit
y
KeV0 1 2 3 4 5
O K's
S K's In L's
In L1
Al K's
Si K's
In L's
(A)
(B)
Rel
ativ
e In
ten
sity
KeV
In66-X
Fisons KEVEX/SIGMA system,an EDS system attached toa Hitachi S-4100 SEM
