Rotating disk electrode , room-temperature

Cu9ln4 and Cu2Se. They performed electrodeposition potentiostatically at room temperature on Ti or Ni rotating disk electrodes from acidic, citrate-buffered solutions. It was shown that the formation of crystalline definite compounds is correlated with a slow surface process, which induced a plateau on the polarization curves. The use of citrate ions was found to shift the copper deposition potential in the negative direction, lower the plateau current, and slow down the interfacial reactions. 

Copper salts are reasonably soluble over a wide pH range, but In and Ga salts only exhibit solubilities above ImM at pH < 3 for In and at pH < 1.5 for Ga (82). Rotating disk electrode experiments show that Cu deposits under mass transfer-controlled conditions on Mo, whereas In deposits under kinetic control at room temperature. There are a few reports on electrodeposition of Cu/In or In/Cu stacks for the realization of CIS semiconductor compounds [83, 84). One technologically interesting report from Penndorf et al. [83] describes the use of copper tape as both the substrate and source of Cu for the formation of CuInS2. Indium was electrode-posited on the copper tape in a roll-to-roU process with remarkably high current densities of 150-200 mAcm with the help of thiourea. CeU efficiencies of up to 6% were reported with this approach. 

Kachoosangi, R.T., Wildgoose, G.G., and Compton, R.G. (2007) Room temperature ionic liquid carbon nanotube paste electrodes overcoming large capacitive currents using rotating disk electrodes. Electroanalysis, 19, 1483-1489. 

Figure 3.6. Hydrogen oxidation current on rotating disk electrode at 20 mV in 0.1 M HCIO4 saturated with 100 ppm CO/H2 at room temperature [69]. (Reproduced by permission of ECS—The Electrochemical Society, from Holleck GL, Pasquarello DM, Clanson SL. Carbon monoxide tolerant anodes for proton exchange membrane fuel cells.)...

Figure 13.7. Polarization curves for O2 reduction reaction on Au/Pt/C (A) and Pt/C (C) catalysts on a rotating disk electrode, before and after 30,000 potential cycles. Sweep rate 10 mV/s rotation rate 1600 rpm. Voltammetric curves for Au/Pt/C (B) and Pt/C (D) catalysts before and after 30,000 cycles sweep rates 50 and 20 mV/s, respectively. The potential cycles were from 0.6 to 1.1 V in an 02-saturated 0.1 M HCIO4 solution at room temperature. For aU electrodes, the Pt loading was 1.95 mg (or 10 nmol) on a 0.164 cm glassy carbon rotating disk electrode. The shaded area in (D) indicates the lost Pt surface area [31]. (From Zhang J, Sasaki K, Sutter E, Adzic RR. Stabilization of platinum oxygen-reduction electrocatalysts using gold clusters. Science 2007 315 220-2. Reprinted with permission from AAAS.)...

Fig. 7 Catalytic activities of Au/Pt/C and Pt/C measured as the currents of reduction obtained before (a) and after (c) 30,000 potential cycles from 0.6 to 1.1 V at the rate of 50mV s of a thin-layer rotating disk electrode in an O -saturated O.IM HCIO solution at room temperature. Corresponding voltammetry curves for the Au/Pt/C and Pt/C electrodes before (b) and after (d) potential cycling...

The ORR has been studied with a rotating ring-disk electrode (RRDE), which can provide theand the H2O2 yield P(H202) at around room temperamre. However, for improving the ORR activity, PEFCs should be operated at high temperature (> 80 °C). In this section, we demonstrate the temperature dependencies of ORR activity and P(H202) at pure Pt (both bulk and supported catalyst) and bulk Pt alloys (Pt-Ni, Pt-Co, and Pt-Fe). 

As mentioned in Sec. 2.1, simple superposition of the respective current-potential curves for the two partial reactions does not always yield the curve obtained with a complete electroless bath. This is illustrated in Fig. 21 [126], in which the current-potential curve obtained with a complete electroless copper bath containing EDTA (curve 1) is compared with the curve obtained in solution in the absence of formaldehyde (curve 2) and with that obtained in solution in the absence of Cu(II) (curve 3). All three curves were recorded at room temperature with a copper disk electrode rotating at 2100 rpm, while scanning the potential in the positive direction... 

The electrochemistry of titanium (fV) has been exanuned in acidic l-ethyl-3-methyUmidazolium chloride/AlClj ([EmimJCl/AlClj) in 1990 by Carlin et al. [180]. It was shown that titaifium is reduced to Ti(lll) and Ti(n) in two one-electron steps, both of which exhibit slow electron-transfer kinetics. Ten years later, Mukhopadhyay et al. smdied the deposition of Ti nanowires at room temperature from 0.24 M TiCl in the ionic liquid l-butyl-3-methylimidazohumbis((trifluoromethyl)sulfonyl)amide [181]. They found that up to six wires grow at constant potential over a period of about 20 min wires exhibit a narrow width distribution of 10 2 nm and have a length of more than 100 nm. The chemical and electrochemical behavior of titanium was examined in the Lewis acidic [EmimlCl/AlClj molten salt at 353.2 K. The electrodeposition of Al-Ti alloys at Cu rotating disk and wire electrodes was investigated by Tsuda et al. [55]. It was found that Al-Ti alloys which contain up to 19% (atomic fraction) titanium, could be electrodeposited from saturated solutions of Ti(II) in the... 

Massaccesi et al. [94] studied in detail the room temperature deposition of copper selenide films onto rotating disk tin oxide electrodes from deoxygenated solutions at pH 2.45 containing ImM CUSO4, 0.1 M K2SO4, and between 0 and 10 mM H2Se03. Two Se(IV) species are present at this pH, and their reduction potentials are given below. 

Zhu, Q. and Hussey, C. L. (2001), Galvanostatic pulse plating of Cu-Al alloy in a chloroaluminate molten salt Room-temperature rotating ring disk electrode studies , J. Electrochem. Soc., 148, 395 02. 

The electrochemical instrumentation used, fabrication of the needle-type sensor with an incorporated Ag/AgCl reference electrode, and electrodeposition of the PPD film have been described previously (14). Rotating disk studies of Nafion and PPD membranes were performed as described elsewhere (79). Nafion membrane thicknesses were determined using ellipsometry (79). Nafion and glucose oxidase membranes were cured for 1 h in an oven, or overnight at room temperature (75). 

---