Special Lecture
Internship at : Department of Chemical Engineering, Katsura Campus, Kyoto University (4th koza)
Duration : Two months (2nd June to 28th July 2014)Presented by : Mr. Jirapat Pakchamsai (Jojo)From : Chulalongkorn University, Thailand.
Influence of Au-addition on some physical properties of Fe-nanoparticles synthesized by gas-injected arc–in-water method
Introduction• Background• Carbon nanomaterials : Carbon nanotubes(CNTs) and Carbonbon nanohorns(CNHs)
• CNH • Properties : • Has a unique structure which is different from CNT• Has high surface area• Has good chemical stability
• Applications : (when combined with metal nanoparticles)• Catalysts support : Catalysts for decomposition of methane by stream to generate hydrogen• Gas sensor• Fuel cell• Energy storage• Drug delivery : Incorporate various molecules inside Single-Wall Nanohorns (SWNH) from
various solutions• Magnetic Application : • Magnetic trap• Magnetic mobility
• Limitation : • Large-scale preparation with high purification is not available
Introduction(2)
• Synthesis Procedure :• Chemical method : • Reduction of ions in aqueous solutions : This method requires
chemicals• Physical method : • Laser ablation : This method requires big instruments• Arc-Discharge : This method is applicable in small-scale experiment and
low cost• Etc.
Introduction(3)• Motivations• In the past :
• Arc-Discharge method can produce CNTs, CNHs, and Metal-CNHs (M-CNHs)• Nitrogen gas injection can increase the yield of CNHs
Plum(2012) : Controlled Syntheses of Various Palladium Alloy Nanoparticles Dispersed in Single-Walled Carbon Nanohorns by One-Step formation Using an Arc Discharge Method: Study various alloy of Pd + Ag, Cu, Ni, Fe, W, Pt, Au, Mo, Nb, and Ti: Observe that if the boiling temperature is higher than arc temperature, there will be NO alloy: Particle size can be estimated by boiling temperature, melting temperature, surface tension, and atomic weight
Au may reduce the particle size
HiramaYamada Ice : Effect of Fe/Fe2O3 loading on catalytic activity of sulfonated single-walled carbon nanohornfor esterification of palmitic acid: Study the effect of Fe
Effect of Fe
MY RESEARCH
Introduction(4)
• Objectives• To study the effects of Au addition on some physical properties• Particle Size Distribution TEM• Composition of Product TEM, XRD, and EDX• Magnetic Properties AC magnetic susceptibility
Experimental Details
• Apparatus and Main Materials• Arc Machine• Nitrogen gas Supplier• Power Supply• Graphite Rods• Distilled Water• Metal Wires (Fe-wire and Au-wire)• Driller
Experimental Details(2)
• Setup Conditions• Distilled Water : 3000mL• Graphite Rod (Anode) : Diameter(Ø) 6.15mm, Length(L) 76mm
(with 2mm Ø hole)• Graphite Rod (Cathode) : Diameter(Ø) 20mm, Length(L) 55mm
(with upper four 2mm Ø holes and lower 10mm Ø hole)• Power Supply : Discharge Current 100A• Velocity of Lower Electrode : 1.5mm/s• Distance of Lower Electrode Travel(Vertically) : 67mm• Time of Reaction : 30s• Nitrogen Gas Flow Rate : 10L/min• Voltage : 30volt 55m
m
45mm
Experimental Details(3)
• Cross-sectional view
Upper Electrode (Cathode)
Lower Electrode (Anode)
Ø 15 mm
Ø 2 m
m
Ø 20 mm
Ø 10 mm
For Pure CNH
Ø 6.15 mm
For Metal-CNH
Ø 2 mmØ 6.15 mm
Experimental Details(4)
• Graphite Rods(Anode) Information• SET A (keep Fe/Au ratio constant + change total metal amount)
• SET B (keep Fe supply amount constant + change Fe/Au ratio)
Diameter(mm) Pitch Distance(mm)
Weight Ratio of Fe/Au
Number of Au-wire Remark
Fe Au
0.3 0.3 1.5 1 1 Twisted together
0.5 0.3 2 1 1 Au in spiral
0.6 0.3 2.5 1 1 Au in spiral
0.8 0.3 3 1 1 Au in spiral
Diameter(mm) Pitch Distance(mm)
Weight Ratio of Fe/Au
Number of Au-wire Remark
Fe Au
0.8 0.3 4 2.906 1 Au in spiral
0.8 0.3 4 1.457 2 Au in spiral
0.8 0.3 4 0.58 5 Au in spiral
A1
A2
B3
B4
A3
A4
B1
Finished Sample
Au-wire Ø 0.3mm
Experimental Details(5)
• Samples PreparationFe-wire Ø 0.8mm
Ø 0.8mm
68mm
76mm
Ø 2mm Graphite Rod (Anode)
8mm To hold wires
Experimental Details(6)
• Experimental Setup
Mot
or S
lider
Stati
c Hol
der
N2
ARC
GAS
GAS
GAS
GAS
GAS
GASGAS
Collect Floating Powder
Must be in the center
Experimental Details(7)
Dry for 1 night
Ready for further Analysis
TEM
XRD
Magnetic property
EDX
Results and Discussions
• Particle Size Analysis• Analyzed by TEM (Transition Electron Microscope)
Raw CNH
100nm
Fe-CNH
Examples of TEM images
50nm 20nm
Results and Discussions(2)Fe-CNH
50nm
Au-Fe-CNH
50nm
Examples of TEM images
With Au-addition, the Fe-nanoparticles seem to be smaller.
Results and Discussions(3)• Examples of TEM images and Histograms
A1 : Au0.3Fe0.3120k
50nm
A4 : Au0.3Fe0.8120k
50nm
0-2 2-4 4-6
6-8 8-10
10-12
12-14
14-16
16-18
18-20
20-22
0
10
20
30
40
50
60
70
0-2 2-4 4-6 6-8 8-10
10-12
12-14
14-16
16-18
18-20
20-22
0
10
20
30
40
50
60
70
Num
ber o
f Pa
rticl
es
Num
ber o
f Par
ticle
s
Size of Particle(nm)Size of Particle(nm)
Results and Discussions(4)SET A (Fe : Au = 1:1)0-2 2-4 4-6 6-8 8-10 10-
12 12-14
14-16
16-18
18-20 20-220102030405060708090
0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-220
10
20
30
40
50
60
70
80
90
0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-220
10
20
30
40
50
60
70
80
90
0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-220
10
20
30
40
50
60
70
80
90
Fe0.3
Fe0.8
Fe0.6
Fe0.5
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.95
6
7
8
9
10
11
12
Diameter of Fe-wire(mm)
Aver
age
size(
nm)
The average particle size is larger when diameter of Fe-wire increases.Addition of Au makes the particle size smaller in most cases.
With AuWithout Au
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.95
6
7
8
9
10
11
12
7.4
8.7 8.6
9.3
Diameter of Fe-wire(mm)
Aver
age
size(
nm) With Au
Without Au
SET B (Fe=0.8, Fe : Au vary)
20 25 30 35 40 45 50 55 60 65 705
6
7
8
9
10
11
12
13
14
Without Au With Au
Aver
age
size(
nm)
Percent of Au in sample (wt%)
Results and Discussions(5)
0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-220
102030405060708090
100
0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-220
102030405060708090
100
0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-220
102030405060708090
100
Fe : Au 2.91(wt%)
Fe : Au 0.58(wt%)
Fe : Au 1.46(wt%)
Size of Particle(nm)
Size of Particle(nm)
Size of Particle(nm)
Num
ber o
f Par
ticle
sN
umbe
r of P
artic
les
Num
ber o
f Par
ticle
s
Without Au
20 25 30 35 40 45 50 55 60 65 705
6
7
8
9
10
11
12
13
14With Au
Percent of Au in sample (wt%)Av
erag
e siz
e(nm
)
There is a maximum point for particle size. This point is in the range of 35-45 percent of Au.
CNH
Fe-Powder
Au-Powder
T1
T2
T3
20 25 30 35 40 45 50 55 60 65 70
Fe0.5Au0.3(same weight)
A2
27
45 65
38
44 64
CFeAu
T = TemplateA = Same weight of Au and FeB = Different weight of Au and FeR = Reference
Inte
nsity
(rel
ative
)
2theta(degree)
Results and Discussions(6)• Alloying Component Determination• Analyzed by XRD (X-Ray Diffraction)
Examples of XRD Patterns from SET A
Alloy
20 25 30 35 40 45 50 55 60 65 70
Fe0.5Au0.3(same weight)
A2
Results and Discussions(7)
2theta(degree)
Examples of XRD Patterns
Alloy
SET A Example : A2 Fe0.5 Au0.3 same weight
35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-500
0
500
1000
1500
2000
2500
3000
experiment Au alloy total
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.90
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Ratio
of A
lloy
and
Au
Diameter of Fe-wire (mm.)
Results and Discussions(8)
2theta(degree)
Inte
nsity
(rel
ative
)
The Ratio of Alloy/Au is calculated by fitting the Lawrence Distribution curve with Experimental curve
Alloy
• There are some consistent information between average particle size graph and Ratio of Alloy/Au graph
Results and Discussions(9)
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.95
6
7
8
9
10
11
12
Diameter of Fe-wire(mm)
Aver
age
size(
nm)
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.90
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Ratio
of A
lloy
and
Au
Diameter of Fe-wire (mm.)
SET A
CNH
Fe-Powder
Au-Powder
20 25 30 35 40 45 50 55 60 65 70
Fe0.8-Au0.3-1wire(diff weight, same length)
T1
T2
T3
B1
27
45 65
38
44 64
CFeAu
T = TemplateA = Same weight of Au and FeB = Different weight of Au and FeR = Reference
Results and Discussions(10)In
tens
ity(r
elati
ve)
2theta(degree)
Examples of XRD Patterns from SET B
Alloy
20 25 30 35 40 45 50 55 60 65 70
Fe0.8-Au0.3-1wire(diff weight, same length)
B1
Results and Discussions(11)
2theta(degree)
Examples of XRD Patterns
Alloy
SET B Example : B1 Fe0.8 Au0.3-1wire (diff weight, same length)
35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-500
0
500
1000
1500
2000
2500
3000
3500
experiment Au alloy total
20 25 30 35 40 45 50 55 60 65 700
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Ratio
of A
lloy
and
Au
Weight percent of Au
Results and Discussions(12)
2theta(degree)
Inte
nsity
(rel
ative
)
The Ratio of Alloy/Au is calculated by fitting the Lawrence Distribution curve with Experimental curve
Alloy
Results and Discussions(13)• Magnetic Susceptibility (χ) Measurement• Analyzed by XacQuan-II instrument• Example : A1
0 5 10 15 20 25 30
-2
-1
0
1
2
3
4
5
0 5 10 15 20 25 300
0.5
1
1.5
2
2.5
3
0 5 10 15 20 25 30
-1000
-500
0
500
1000
1500
0 5 10 15 20 25 300
200400600800
1000120014001600
0 5 10 15 20 25 30
-2
-1
0
1
2
3
4
5
0 5 10 15 20 25 300
0.51
1.52
2.53
3.54
4.5
CNH
Fe0.3Au0.3
Fe-powder
Re(χ
)/g
Re(χ
)/g
Re(χ
)/g
Frequency(kHz)
Frequency(kHz)
Frequency(kHz)
Frequency(kHz)
Frequency(kHz)
Frequency(kHz)
Im(χ
)/g
Im(χ
)/g
Im(χ
)/g
Re = Real PartIm = Imaginary Part
20 25 30 35 40 45 50 55 60 65 700
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Ratio
of A
lloy
and
Au
Percent of Au
Results and Discussions(14)
20 25 30 35 40 45 50 55 60 65 700
5
10
15
20
25
30
SET A SET B
Max
(Re(
χ)/g
)
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.90
10
20
30
40
50
60
With AuWithout Au
Max
(Re(
χ)/g
)
Diameter of Fe-wire (mm)Percent of Au
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.90
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Ratio
of A
lloy
and
Au
Diameter of Fe-wire (mm.)
For SET A (keep Fe/Au in feed, change total metal), alloying with Au leads to the increase of magnetic susceptibility. In comparison with “without Au” case, magnetic susceptibility is increased by adding Au. Such a trend is against initial expectation.
But for SET B (keep Fe in feed at high value, change Fe/Au ratio), alloying with Au leads to the decrease of magnetic susceptibility. This is initially expected.
SET A and SET B are contradicted. It is noteworthy that the influence of Au on magnetic property can be reversed if Au is remarkably contained.
0 1 2 3 4 5 6 7 80
5000
10000
15000
20000
25000
30000
Energy(kV)
Inte
nsity
(rel
ative
)
x20
Au
Fe
C
C
Results and Discussions(15)• Composition Determination• Analyzed by EDX (Energy Dispersive X-ray spectroscopy)
Example : A1 Fe0.3 Au0.3 same weight
Results and Discussions(16)
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.900.5
11.5
22.5
33.5
44.5
Enric
hmen
t fa
ctor
of A
u
Diameter of Fe-wire (mm.)
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.905
101520253035
Diameter of Fe-wire (mm.)
Perc
ent o
f met
al in
clus
ion
Enrichment factor = (Au wt%/Fe wt%) in product (Au wt%/Fe wt%) in sample
SET A
Results and Discussions(17)
20 25 30 35 40 45 50 55 60 65 700
1
2
3
4
5En
richm
ent o
f Au
Percent of Au
20 25 30 35 40 45 50 55 60 65 700
10
20
30
40
50
Perc
ent o
f met
al in
clus
ion
Percent of Au
SET B
By taking possible error into account,I believe that there is a tendency that increasing metallic amount simply lead to increase of metal inclusion.
Enrichment factor = (Au wt%/Fe wt%) in product (Au wt%/Fe wt%) in sample
Conclusions
SET A(keep Fe/Au ratio in fee, change total metal spply)SET B(keep Fe supply, change Fe/Au weight ratio)
CNHs dispersed with Fe/Au alloy nanoparticles are produced by Gas-injected arc-in-water method with two variation sets.
Focus: investigation on controllability of alloy particle size, Alloy/metal ratio, Fe/Au ratio, and magnetic susceptibility
1. Increase of metal supply leads to larger particle diameter. 2. Adding Au leads to reduce the Average Particle Size. 3. Increase metals in feed leads to increase alloy content.4. Increase of metal content leads to reduced Au-enrichment.5. Magnetic susceptibility is expected to be lower by alloying
with Au. But large Au content may overshadow this trend.
Main findings
VIDEO clip for Experimental Setup
Credit : Tanemori San
THANK YOU
Jirapat Pakchamsai
