Template-based FeNiCo Nanowire Electrodeposition Involving ...
Graduate Category: Engineering and Technology Degree Level: PhD student Abstract ID# 1083
Template-based FeNiCo Nanowire Electrodeposition Involving Hydrogen Evolution Reaction Deyang Li and Elizabeth J. Podlaha Result
Introduction Fabrication of Ni , Fe, Co single or codeposited nanowires in both polycarbonate(PC) and anodized alumina oxidized (AAO) by DC or pulsing current has been extensively investigated[1-4]. However, there is a lack of work on alloy nanowires by DC current with gas evolving side reactions.
Surfactant effect (various SLS concentrations @E = -1.19 V (vs SCE) ) 1 mM
0 mM
SLS
7 mM
0.
Challenges Side reaction due to hydrogen evolution reaction b
c
Local pH rises
AAO
OHOH-
H+
H+
H+
OHH+
-0.03
SLS = 1 mM -0.045
SLS = 7 mM
-0.075 0.
2000.
Cathode
2H+ + 2e- = H2 Kw = [H+][OH-] •
SLS = 0 mM
-0.06
Cathode a.Blocking the active sites b.Rough edge c.Porous structure, easily to break apart d.a, b, and c can happen simultaneously
Due to hydrogen bubbles, blocking surface
-0.015
i A/cm2
H2 bubbles a
AAO current density profile @ E= 1.19 V
Short ~ 4 microns
Long ~ 20 microns
H+
concentration decreases, local pH increases
Medium ~ 12 microns
High current efficiency
Low current efficiency
1
4000.
24
6000.
8000.
t /s 100 >3000 bubbles/sec
H2 bubble
Schematic of bubbles release at a micros-electrode[6].
• Short nanowires obtained without SLS • SLS affects the deposition rate: at low SLS concentration the deposition rate increases, but at high SLS concentration the deposition rate decreases
0.1
0.0
0.4
mM SLS
7
Literature One solution to manage side reaction effect - pulse deposition Membrane material and current condition (AAO and PC membranes @constant current density and 1 mM SLS) Dissimilar layers
AAO
PC
-0.03 A/cm2
XRF result
PC
-0.03 A/cm2
-0.105 A/cm2
The average composition of each metal element in the thin film can be tested by XRF.
Hana Kim’s PhD thesis: Super Invar nanowire obtained by pulse current [5].
Elemental composition 100
Objectives
AAO -0.03
90
PC -0.03
PC -105
80
• DC Fabrication of FeNiCo nanowire in both AAO and PC membranes • Surfactant effect: to exam the surfactant (sodium lauryl sulfate) concentration on nanowire morphology. • Membrane material and current condition: to investigate various current conditions on the nanowire morphology
70
69
66
60 50
53 45
40
32
28
30 20 10
Long and robust nanowires
Experimental
Short nanowires
Long nanowires
3
2
2
Fe
Ni
Co
The unit of current density is A/cm2
Diameter / nm
Thickness / um
AAO
200
60
PC
200
10 Au sputtering on one side
-0.6 -0.8 -1. -1.2
Under the agitation
Cathode Template
current Au film
Growth
Membrane dissolution AAO: NaOH PC: DCM
750.
1500. t /s
2250.
E ~ -0.83 V
-1.
-1.4
-1. -1.2
-1.2
3000.
E ~ -1.13 V
-0.8
0.
2000.
4000.
6000.
8000.
t /s
-1.4 0.
350.
700. t /s
1050.
In AAO, hydrogen bubbles are able to go through membrane matrix.
In PC, hydrogen bubbles are confined in the deep recess.
1400.
Reference
Anode Pt mesh
The schematic of experimental setup. Reference Electrode is applied to measure the cathode potential.
Applying
0.
-0.6 -0.8
Possible reasons: • Higher hydrogen permeability in AAO than in PC • Hydrogen side reaction is dominating at lower current density
-0.6 E /V (vs SCE)
E ~ -1.20 V
-1.4
Membrane Membrane
Reference electrode
PC potential profile @i = -0.105 A/cm2
PC potential profile @ i = -0.03 A/cm2 E /V (vs SCE)
0.72 M 0.155 M 0.005 M 0.5 M 0.011 M 0 mM, 1 mM, 7 mM 2 40 oC
AAO potential profile @ i = -0.03 A/cm2 E / V (vs SCE)
Nickel Sulfate Iron Sulfate Cobalt Sulfate Boric acid Ascorbic Acid SLS pH Temperature
H2 bubbles
0
Electrolyte Counter electrode
• AAO gives longer nanowires at low current density • The Fe and Ni compositions are dependent on the potential
1. 2. 3. 4. 5. 6.
Motoyama, Munekazu, et al. J. Electrochem. Soc. 157.6 (2010) Ghahremaninezhad, A., et al. J. Alloys Compd. 480.2 (2009) Hu, Xing, et al. J. Electrochem. Soc 162.12 (2015) Dragos, Oana, et al. J. Electrochem. Soc 163.3 (2016) Hana Kim, PhD Dissertation, 2012, Northeastern University Fernandez, Damaris, et al. Langmuir 30.43 2014
Acknowledgements Nanowires
The authors acknowledge and thank Roche Diagnostics for support of this project.
Conclusion •Fabrication of FeNiCo nanowire by DC current was achieved successfully •The current efficiency can be affected by surfactant (SLS) concentration •Hydrogen side reaction effect is better managed in AAO than in PC
Template-based FeNiCo Nanowire Electrodeposition Involving Hydrogen Evolution Reaction Deyang Li and Elizabeth J. Podlaha Result
Introduction Fabrication of Ni , Fe, Co single or codeposited nanowires in both polycarbonate(PC) and anodized alumina oxidized (AAO) by DC or pulsing current has been extensively investigated[1-4]. However, there is a lack of work on alloy nanowires by DC current with gas evolving side reactions.
Surfactant effect (various SLS concentrations @E = -1.19 V (vs SCE) ) 1 mM
0 mM
SLS
7 mM
0.
Challenges Side reaction due to hydrogen evolution reaction b
c
Local pH rises
AAO
OHOH-
H+
H+
H+
OHH+
-0.03
SLS = 1 mM -0.045
SLS = 7 mM
-0.075 0.
2000.
Cathode
2H+ + 2e- = H2 Kw = [H+][OH-] •
SLS = 0 mM
-0.06
Cathode a.Blocking the active sites b.Rough edge c.Porous structure, easily to break apart d.a, b, and c can happen simultaneously
Due to hydrogen bubbles, blocking surface
-0.015
i A/cm2
H2 bubbles a
AAO current density profile @ E= 1.19 V
Short ~ 4 microns
Long ~ 20 microns
H+
concentration decreases, local pH increases
Medium ~ 12 microns
High current efficiency
Low current efficiency
1
4000.
24
6000.
8000.
t /s 100 >3000 bubbles/sec
H2 bubble
Schematic of bubbles release at a micros-electrode[6].
• Short nanowires obtained without SLS • SLS affects the deposition rate: at low SLS concentration the deposition rate increases, but at high SLS concentration the deposition rate decreases
0.1
0.0
0.4
mM SLS
7
Literature One solution to manage side reaction effect - pulse deposition Membrane material and current condition (AAO and PC membranes @constant current density and 1 mM SLS) Dissimilar layers
AAO
PC
-0.03 A/cm2
XRF result
PC
-0.03 A/cm2
-0.105 A/cm2
The average composition of each metal element in the thin film can be tested by XRF.
Hana Kim’s PhD thesis: Super Invar nanowire obtained by pulse current [5].
Elemental composition 100
Objectives
AAO -0.03
90
PC -0.03
PC -105
80
• DC Fabrication of FeNiCo nanowire in both AAO and PC membranes • Surfactant effect: to exam the surfactant (sodium lauryl sulfate) concentration on nanowire morphology. • Membrane material and current condition: to investigate various current conditions on the nanowire morphology
70
69
66
60 50
53 45
40
32
28
30 20 10
Long and robust nanowires
Experimental
Short nanowires
Long nanowires
3
2
2
Fe
Ni
Co
The unit of current density is A/cm2
Diameter / nm
Thickness / um
AAO
200
60
PC
200
10 Au sputtering on one side
-0.6 -0.8 -1. -1.2
Under the agitation
Cathode Template
current Au film
Growth
Membrane dissolution AAO: NaOH PC: DCM
750.
1500. t /s
2250.
E ~ -0.83 V
-1.
-1.4
-1. -1.2
-1.2
3000.
E ~ -1.13 V
-0.8
0.
2000.
4000.
6000.
8000.
t /s
-1.4 0.
350.
700. t /s
1050.
In AAO, hydrogen bubbles are able to go through membrane matrix.
In PC, hydrogen bubbles are confined in the deep recess.
1400.
Reference
Anode Pt mesh
The schematic of experimental setup. Reference Electrode is applied to measure the cathode potential.
Applying
0.
-0.6 -0.8
Possible reasons: • Higher hydrogen permeability in AAO than in PC • Hydrogen side reaction is dominating at lower current density
-0.6 E /V (vs SCE)
E ~ -1.20 V
-1.4
Membrane Membrane
Reference electrode
PC potential profile @i = -0.105 A/cm2
PC potential profile @ i = -0.03 A/cm2 E /V (vs SCE)
0.72 M 0.155 M 0.005 M 0.5 M 0.011 M 0 mM, 1 mM, 7 mM 2 40 oC
AAO potential profile @ i = -0.03 A/cm2 E / V (vs SCE)
Nickel Sulfate Iron Sulfate Cobalt Sulfate Boric acid Ascorbic Acid SLS pH Temperature
H2 bubbles
0
Electrolyte Counter electrode
• AAO gives longer nanowires at low current density • The Fe and Ni compositions are dependent on the potential
1. 2. 3. 4. 5. 6.
Motoyama, Munekazu, et al. J. Electrochem. Soc. 157.6 (2010) Ghahremaninezhad, A., et al. J. Alloys Compd. 480.2 (2009) Hu, Xing, et al. J. Electrochem. Soc 162.12 (2015) Dragos, Oana, et al. J. Electrochem. Soc 163.3 (2016) Hana Kim, PhD Dissertation, 2012, Northeastern University Fernandez, Damaris, et al. Langmuir 30.43 2014
Acknowledgements Nanowires
The authors acknowledge and thank Roche Diagnostics for support of this project.
Conclusion •Fabrication of FeNiCo nanowire by DC current was achieved successfully •The current efficiency can be affected by surfactant (SLS) concentration •Hydrogen side reaction effect is better managed in AAO than in PC
