The endoscope is one of the most extensively used medical devices. Endoscopes are deterged with extreme care because they are inserted directly in the body. Electrochemical disinfection using a palladium-coated carbon cloth electrode was applied to deterge a rod-shaped tool as a potential endoscope-deterging method because it required no toxic agent, did not cause secondary pollution, and provided an eco-friendly disinfection system. The anodic polarization of palladium in an NaCl-containing solution led to the effective generation of disinfective ClO− and the simultaneous gas evolution caused natural convection that increased the disinfection efficacy. Electrochemical degreasing could also be attained by alternating between positive and negative electrode polarities.
Layered Manganese and aluminum double hydroxides (Mn-Al LDH) were electrochemically synthesized on a Ni, or a Pt substrate by galvanostatic electrochemical reduction of Mn(NO3)2 and Al(NO3)3 aqueous solutions mixtures. The obtained XRD data indicated that the interlayer spacing of the Mn-Al LDH was 0.87 nm and was in good agreement with that reported for NO3/Mn-Al LDH. The contents of trivalent cation, Al3+, in the products were almost identical to those in the corresponding electrolyte solutions. During electrochemical oxidation and reduction of NO3/Mn-Al LDH precipitated from a Mn(NO3)2 and Al(NO3)3 aqueous solutions 3:1 mixture in a 2 mol dm−3 KOH solution, Al contents in the NO3/Mn-Al LDH deviated products decreased by ca. 0.2. Although the dissolution of Al3+ in the LDHs occurred at the first electrochemical oxidation in a 2 mol dm−3 KOH solution, reversible redox peaks were observed at around −0.2 V vs. Hg/HgO after 2nd cycle of CVs.
EDLC and Li-ion Capacitor are attractive devices for accumulation of electricity. Their electrodes are made mainly from activated carbon. SATO-KOMUSHO Corporation has made activated carbon from used-cotton-towels. If it could be used for their electrode material, it would be good for the local industry. Hence, we have researched the possibility of carbonized used-cotton-towels as an electrode material. This research investigated an optimum compounding ratio by changing the ratio of a binder and conductive additives in order to obtain an essential capacity of the carbon material. Its capacity was ca. 100 F g−1 and proved to be as large as that of current commercial electrode.
In order to apply stepped light-induced transient measurements of photocurrent and voltage (SLIM-PCV) to obtain electron diffusion coefficients and lifetimes in dye-sensitized solar cells (DSCs), electron density gradient in the electrode must be small so that the density can be approximated as a constant value. In this paper we prepared DSCs with two different dyes with various thicknesses of TiO2 electrodes, and apply SLIM-PCV with two different wavelengths of the lasers. Required conditions of the DSCs for the measurements and methods to check the validity of the measurements are discussed.
We have designed an electrodeposition system employing multiple rotating disc electrodes (RDE) in a single electrochemical bath, with an aim to develop a mean to obtain homogeneous zinc oxide (ZnO) thin films with a high reproducibility, as the reaction is known to be strongly limited by mass transport. Substrates such as F-doped SnO2 (FTO) coated glass having no electric conduction on the back side were furnished into a geometry of RDEs employing conductive and insulating tapes. The shape of the active electrode area was determined through tests. Also, the influence of the position of the RDE in the electrochemical bath was tested. Having confirmed that neighboring RDEs do not interfere each other, eight RDEs were placed like a roulette in a single electrolytic bath. The resulting eight ZnO samples electrodeposited by using the eight RDE system were almost identical with the standard deviation of less than 0.3% for their thickness.
An electrochemical recycling process of the noble metal such as Pt and Ru from the membrane electrode assemblies (MEAs) in fuel cells was investigated for the environment-friendly process without aqua regia. The dissolution rate of Pt in HCl solution was about 50 times as fast as those in H2SO4 and HClO4 solutions. The Pt dissolution rate increased linearly with HCl concentration. Pt dissolution under fluctuating potential using saw-tooth wave is 15 times faster than that under constant potentials. The electrochemical dissolution method can also be applied to the dissolution of Pt and Ru in the PtRu catalysts. The chemical methods using aqua regia, HCl-H2O2 mixed solution, and HCl only were also investigated for the comparison as the electrochemical methods. The Pt dissolution rate decreased according to the order of aqua regia > 11.3 M HCl-0.36 M H2O2 > 1 M HCl-10.3 M H2O2 > 1 M HCl. The vaporization rate of oxidants (NOCl and Cl2) from aqua regia at 333 K was 40 times as fast as that at 298 K by a spectrochemical method.
Novel room-temperature ionic liquids based on trialkylphosphonium cations and their physicochemical characterizations are presented in this report. It was found that ionic liquids based on trialkylphosphonium cations together with bis(trifluoromethylsulfonyl)amide anion were lower melting, lower viscous and more conductive than the corresponding trialkylammonium ionic liquids. Particularly, triethylphosphonium bis(trifluoromethylsulfonyl)amide exhibited the lowest viscosity and highest conductivity in the trialkylphosphonium-based ionic liquids. The protic ionic liquid electrolyte based on triethylphosphonium bis(trifluoromethylsulfonyl)amide also showed relatively high conductivity when compared to the corresponding ammonium ionic liquid electrolyte.
The corrosion types of Q235 carbon steel and nuclear grade 304 stainless steel (304 NG SS) in different solutions are investigated by electrochemical noise (EN) technique. EN data are analyzed by using phase space reconstruction theory. With the obtained correlation dimension from the phase space reconstruction, the chaotic behavior of EN is quantitatively evaluated. It is concluded that local corrosion shows a higher correlation dimension while passivation shows a lower correlation dimension. We propose that the correlation dimension increases with the complexity and uncertainty of the signals from passivation to local corrosion, which is the physical meaning of correlation dimension for EN.
In this paper, cyclic voltammograms of the film electrodes containing Pb active materials and sodium lignosulfonate formed on Pb plate have been measured in sulfuric acid solution. Discharging capacity decreases and charging capacity increases with longer alkaline hydrothermal treatment of sodium lingosulfonate in the film electrodes. These film electrodes can be used for the cyclic voltammetry regardless of the solubility of the lignin preparations in the electrolyte.
A platinum-tungsten oxide binary electrocatalyst, Pt-WO3, has been prepared on a carbon black support to examine the effects of the introduction of WO3 on the anodic oxidation of ethanol at Pt electrocatalyst. Specific activity for the ethanol oxidation, evaluated from voltammetric responses, was higher at the catalyst deposited on the oxide, Pt-WO3/C, than at the catalyst without the oxide, Pt/C. However, no improvement in the continuous activity was observed for the catalyst with WO3, suggesting that the effect of WO3 introduction was limited to the initial step of the anodic oxidation of ethanol at the Pt electrocatalyst.