Potentiostatic electrodeposition

The potentiostatic electrodeposition of iron selenide thin films has been reported recently in aqueous baths of ferric chloride (FeCb) and Se02 onto stainless steel and fluorine-doped TO-glass substrates [193], The films were characterized as polycrystalline and rich in iron, containing in particular a monoclinic FesSea phase. Optical absorption studies showed the presence of direct transition with band gap energy of 1.23 eV. 

Within the scope of thermoelectric nanostructures, Sima et al. [161] prepared nanorod (fibril) and microtube (tubule) arrays of PbSei. , Tej by potentiostatic electrodeposition from nitric acid solutions of Pb(N03)2, H2Se03, and Te02, using a 30 fim thick polycarbonate track-etch membrane, with pores 100-2,000 nm in diameter, as template (Cu supported). After electrodeposition the polymer membrane was dissolved in CH2CI2. Solid rods were obtained in membranes with small pores, and hollow tubes in those with large pores. The formation of microtubes rather than nanorods in the larger pores was attributed to the higher deposition current. 

Fig. 4.3 Kinetics of potentiostatic electrodeposition of germanium from the oxyfluoride melt...

Popov KI, Maksimovic MD, Tmjancev JD, Pavlovic MG (1981) Dendritic electrocrystallization and the mechanism of powder formation in the potentiostatic electrodeposition of metals. J Appl Electrochem 11 239-246... 

Fig. 6.11 (a) Particle size distribution curves for Cu powders obtained by potentiostatic electrodeposition on Pt electrodes, (b) particle size distribution curves for Cu powders obtained by galvanostatic electrodeposition on Pt electrodes. The surface area of the electrode 0.63 cm and (c) particle size distribution curves for Cu powders obtained by the potentiostatic and galvanostatic (the average current in the potentiostatic regime) electrodepositions on Cu electrodes. The surface area of the electrode 0.63 cm (Reprinted from Refs. [6, 7, 62] with kind permission from Springer)... 

Anyway, the effect of the increasing current density in the galvanostatic electrodeposition is qualitative same as the increase of overpotential in potentiostatic electrodeposition, and the essence of the particle size distribution curve formation is the same in both cases. 

The electrodeposition of three-dimensi(Mial (3D) macroporous ZnSe semiconductors has also been reported [101]. Macroporous structures of ZnSe have been fabricated because highly ordered macroporous structures consisting of semiconductors with high refractive indexes are well-known to be photonic crystals. A template consisting of 3D-ordered arrays of silica spheres is employed. Galvanostatic and potentiostatic electrodeposition is then carried out to deposit ZnSe into the interstitial spaces between the silica... 

Fig. 3.22 Particle size distribution curves for copper powders obtained by potentiostatic electrodeposition on platinum electrodes (Reprinted from [6, 83] with permission from Springer.)...

The particle size distribution curves for copper powders obtained on the platinum electrodes in galvanostatic regime at currents of 28.6, 52.0, and 133 mA are shown in Fig. 3.23. The selected currents corresponded to average currents recorded in potentiostatic electrodepositions at overpotentials of 600,700, and 800 mV, respectively [83]. The formation of larger particles and less narrow distribution curves in the galvanostatic regime than those formed in the potentiostatic... 

There is an important difference between disperse deposits formed in galvanostatic and potentiostatic conditions. In potentiostatic electrodeposition, the properties of disperse deposits mainly depend on overpotential of electrodeposition. The electrodeposition overpotential remains constant during deposition time, as well as the real current density, and the structure of disperse deposits does not change with the electrodeposition time. Hence, it can be expected that both the stmcture of powder particles and the properties of powder (as association of different powder particles) on the macrolevel do not depend on the electrodeposition time. 

Yamauchi et al. developed a modified version of liquid crystalline templation where liquid crystallinity appears progressively during ethanol solvent evaporation. This technique was used for the templated potentiostatic electrodeposition at -0.144 V vs. SCE of 50-800 nm PtRu particles wifli internal mesochannels [244]. 

Hariri, M. B. Dolati, A. Moakhar, R. S. The potentiostatic electrodeposition of gold nanowire/nanotube in HAUCI4 solutions based on the model of recessed cyhndrical ultramicroelectrode array. J. Electrochem. Soc. 2013,160, D279-D288. 

Pt-Ir/Au Potentiostatic electrodeposition fee Ptvolrao alloy Cyclic voltanunetry at room temperature in 2-50mMNH3-t0.1 M KOH solution Peak cinrent density increased linearly from ca. 0.12 to ca. 0.25 mA cm (i/= 10 mV s ) with 41... 

Pt/graphite Pulsed potentiostatic electrodeposition Pt layer consisting of aggregates Cyclic voltammetry at room temperature in 0.1 MNH3-t0.2 M NaOH Peak current density varied from ca. 15 mA to ca. 32 mA (y = 20 mV s ), depending on the deposition potential 43 D. 2, 0... 

Pt black Potentiostatic electrodeposition Pt film with rough surface Cyclic voltammetry at room temperature in 0.1 MNH3-tl MKOH Peak current density 22.5 mA cm (y = 5mV s ) 44... 

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