2.5 Dilatometric Detection of Strain Change for Nano-Porous Metal Electrode
63
2.5 Dilatometric Detection of Strain Change
for Nano-Porous Metal Electrode
In situ dilatometry has been developed for measurement of the changes in strain
of a nano-porous metal electrode as a function of potential in electrolyte solution
[44, 45]. Furthermore, the changes in strain can be converted to the change in surface
stress if the bulk modulus and specific surface area of a nano-porous metal are known
[46, 47]. The nano-porous Pt electrode [44, 46, 47] was prepared by consolidating
commercial Pt black having a grain size of 6 nm, while the nano-porous Au electrode
[45, 48, 49] was prepared by dealloying a master alloy Ag 75 Au 25 (atomic%) in 1 M
HClO 4 solution under potentiostatic control. The nano-porous Au–Pt alloys can be
also prepared by dealloying homogeneous master alloys (Au 1−x Pt x ) 25 Ag 75 in 1 M
HClO 4 solution [50].
Scanning electron micrograph (SEM) of the fracture surface of the nano-porous Pt
sample showed the bi-continuous structure, consisting of an interconnected network
of nanometer-sized Pt crystallites and an interconnected pore space [44, 46, 47].
Similarly, the SEM of the nano-porous Au sample showed the bi-continuous (spongelike open-cell) structure with a ligament size of about 20 nm while maintaining the
original shape of the alloy sample [48]. Figure 2.17 represents a schematic illustration
of the experimental setup for in situ dilatometry of a nano-porous metal electrode [48].
The nano-porous Pt electrode (e.g., 1.8 mm in length and 1.5 mm in diameter) is set
in the sample space of a commercial dilatometer (Netzsch
® 402C) encapsulated in a
miniaturized electrochemical cell [47]. The sample compartment, which contains the
Potentiostat
Inductive displacement
sensor
CE
RE
Pushrod
Nano-porous
metal (WE)
Miniaturized
electrochemical cell
WE: Working electrode
CE: Counter electrode
RE: Reference electrode
Dilatometer
Fig. 2.17 Schematic illustration of the experimental setup for in situ dilatometry of a nano-porous
metal electrode [48]. Modified from [48], Copyright 2008, with permission from Elsevier
63
2.5 Dilatometric Detection of Strain Change
for Nano-Porous Metal Electrode
In situ dilatometry has been developed for measurement of the changes in strain
of a nano-porous metal electrode as a function of potential in electrolyte solution
[44, 45]. Furthermore, the changes in strain can be converted to the change in surface
stress if the bulk modulus and specific surface area of a nano-porous metal are known
[46, 47]. The nano-porous Pt electrode [44, 46, 47] was prepared by consolidating
commercial Pt black having a grain size of 6 nm, while the nano-porous Au electrode
[45, 48, 49] was prepared by dealloying a master alloy Ag 75 Au 25 (atomic%) in 1 M
HClO 4 solution under potentiostatic control. The nano-porous Au–Pt alloys can be
also prepared by dealloying homogeneous master alloys (Au 1−x Pt x ) 25 Ag 75 in 1 M
HClO 4 solution [50].
Scanning electron micrograph (SEM) of the fracture surface of the nano-porous Pt
sample showed the bi-continuous structure, consisting of an interconnected network
of nanometer-sized Pt crystallites and an interconnected pore space [44, 46, 47].
Similarly, the SEM of the nano-porous Au sample showed the bi-continuous (spongelike open-cell) structure with a ligament size of about 20 nm while maintaining the
original shape of the alloy sample [48]. Figure 2.17 represents a schematic illustration
of the experimental setup for in situ dilatometry of a nano-porous metal electrode [48].
The nano-porous Pt electrode (e.g., 1.8 mm in length and 1.5 mm in diameter) is set
in the sample space of a commercial dilatometer (Netzsch
® 402C) encapsulated in a
miniaturized electrochemical cell [47]. The sample compartment, which contains the
Potentiostat
Inductive displacement
sensor
CE
RE
Pushrod
Nano-porous
metal (WE)
Miniaturized
electrochemical cell
WE: Working electrode
CE: Counter electrode
RE: Reference electrode
Dilatometer
Fig. 2.17 Schematic illustration of the experimental setup for in situ dilatometry of a nano-porous
metal electrode [48]. Modified from [48], Copyright 2008, with permission from Elsevier