Electrolysis of pure water in a thin layer cell

Abstract

Current-voltage curves were obtained at parallel platinum electrodes in the thin layer cell including pure water. They were under the steady state in the voltage domain from 1.0 V to 1.3 V when the distance of the electrodes was less than 100 m. The solution resistance obtained from the current-voltage curve was much smaller than that predicted from the resistivity of pure water. The reason can be explained in terms of generation and accumulation of hydrogen ion and hydroxide ion before the recombination reaction. These kinetically survived ions decrease the resistance, and enhance the electrolysis rate. We subtract the reaction-controlled current-voltage curves from the overall curves to evaluate ion-included solution resistance. The resistivity of the solution averaged in the cell increased with an increase in the distance between the electrodes. In order to understand the above behavior, we calculated concentration profiles of the ions and potential distribution in the cell on the basis of Nernst-Planck equation including dissociation kinetics of water.

Salt-free electrolysis of water facilitated by hydrogen gas in thin layer cell

“…The electrodes and the space were coated using a polyethylene vessel, which was a part of a bellows pipette. 12 Pure water was inserted into the vessel through a hole at the top of the vessel by means of a syringe.…”

“…The voltammograms in the thin layer cell did not show any limiting current, but were similar to those of pure water. 12 The disappearance of limiting current may be ascribed to such a large overpotential difference between the cathodic and the anodic reaction of dioxygen that it may overlap with the wave of water decomposition.…”

“…11 A thin layer cell acts as a microreactor, in that it can cause electrolysis without supporting electrolyte, which is demonstrated by electrolysis of pure water. 12 Once a very small amount of water is electrolyzed into H + and OH -, these ions enhance electric conduction in the cell. Change in conductivity during electrolysis has been addressed by studies in the field of microelectrode voltammetry.…”

A model for the voltammetric behaviour of TiO2 memristors

“…More recently, the Nernst Planck-Poisson equation was used for nanometre-thick layers for a model ferrocene compound under steady-state conditions [26] and water electrolysis [27] in the absence of a deliberately added electrolyte. In each of these cases, migration and mass transport current were calculated.…”

On-Line Monitoring the Growth of E. coli or HeLa Cells Using an Annular Microelectrode Piezoelectric Biosensor

“…With the development of microelectronic manufacturing technology and microsensors, many array microelectrodes have been used as the piezoelectric biosensor receptor. Among these, the interdigital microelectrode (IDME) exhibits more advantages than conventional electrodes, such as a micro-scale structure, a high steady-state current density, a low ohm/voltage drop, and a rapid response time and mass transfer between the electrodes [3,4,5]. Thus, an IDME can be used in the electrolyte solution system with a high impedance background to detect cell or microbial culture [6].…”