Deposition methods potential control electrodeposition

Based on cathodic electrodeposition of Ti02 and W03 films, de Tacconi and coworkers (2003) provided a method to cathodically electrodeposit Ti02/W03 composite films via the control of a pulsed deposition potential. By mixing the deposition baths for both Ti02 and W03, the authors applied a pulsed potential... 

Here, we develop the principle of the potential step method for a particularly simple reaction, namely, the electrodeposition of a metal under conditions where the deposition rate is controlled by mass transport. 

Codeposition produces some of the better II-VI electrodeposits and, as can be seen in Table 1, has been used and studied extensively. Aqueous codeposition of CdTe serves as a good example of the method. The deposition is usually performed at an underpotential for Cd, at a potential where the Cd deposits exclusively on previously deposited Te. Te, on the other hand, is more noble than Cd and is thus deposited at an overpotential. The tellurite concentration, however, is kept far below that of the Cd+ so there is a large excess of Cd+l As soon as Te deposits, Cd quantitatively underpotentially deposits on top, providing control over deposit stoichiometry. 

Electrodeposition of dissolved precursors (especially in aqueous solutions) is a low cost and scalable method which is well suited to the mass production of thin films of metal-oxide semiconductors such as Ti02, Cu20, WO3, and ZnO. Control of temperature, pH and the deposition potential are important because the corresponding electrochemical reactions within the deposition bath mainly depend on these parameters. 

The electrodeposition technology has proven to be the least expensive, effective, and readily adoptable method to deposit Ag substrates for reliable SERS substrates with good reproducibility. It allows the preparation of nanostructure patterns by controlling the amount of composition, deposition time, temperature, and applied potential. The SERS substrates prepared by electrodeposition were a good candidate for the fabrication of a reproducible substrate. In principle, most of the metals including Au [55], Cu [56], and Ag [57-59] can be electrodeposited from aqueous solutions. 

In order to study the influence of the surface composition of the thin film electrode on IR features of CO adsorption, nm-Pt/GC and nm-Ru/GC electrodes were modified with Ru and Pt, respectively. Modifications to the Pt on the nm-Ru/GC surface and the Ru on the nm-Pt/GC surface were carried out by employing an electrodeposition method [48]. The nm-Pt/GC or nm-Ru/GC electrode was introduced into 0.1 M H2SO4 solution containing ImM Ru or Pt" ions, and the potential was cycled between —0.25 and 0.40 V at a scan rate of 50mV s. The quantity of Pt deposited on the nm-Ru/GC surface or Ru deposited on the nm-Pt/ GC surface was controlled by varying the number of potential cycles that initiated the deposition. 

Electrodeposition is another method used to produce metal nanoparticles on CNTs. This process was performed in a two electrode arrangement in a solution containing the CNTs with HAUCI4, K2PtCl4, or (NH4)2PdCl4. As a result of this study, Au, Pt, and Pd nanoparticles were deposited on the CNTs by controlling the deposition potential, duration of the pulse, and the concentration of the metal salt in the electrochemical system (Quinn et al. 2005). 

Primary applications of coulometry, such as in the electrodeposition of metals, are limited by the voltage resolution available. In order to deposit one metal in the presence of others, the potential of the cathode must be controlled with precision, an operation requiring a three-electrode electrolytic cell together with a potentiostat, a method introduced by Hickling in 1942 (37). (The principles involved in the choice of potential and the degree of separation possible lie beyond the scope of this article.)... 

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