Supporting electrolyte

About: Supporting electrolyte is a research topic. Over the lifetime, 5011 publications have been published within this topic receiving 104172 citations.

Effects of electrolyte on the electrocatalytic activities of RuO2/Ti and Sb–SnO2/Ti anodes for water treatment

Abstract: The study of high efficiency electrochemical water treatment systems is of great importance in contributing to a sustainable water supply. In this study, we prepared RuO2/Ti and Sb–SnO2/Ti electrodes and investigated their electrocatalytic activities for the oxidation of water and three model substrates (methylene blue, acid orange 7, and 4-chlorophenol) in two supporting electrolytes: NaCl vs. Na2SO4. Irrespective of the electrolyte, the particulate RuO2/Ti anode was found to oxidize water at ca. 0.8 V lower potential ranges with significantly higher currents than the cracked-mud type of Sb–SnO2/Ti, indicating that the latter is more suitable for substrate oxidation. In the system of Sb–SnO2/Ti anode–stainless steel cathode couple, the degradation rates of all the substrates were highly enhanced in NaCl, whereas their complete oxidation (i.e., CO2 evolution) occurred more markedly in Na2SO4. Additional detailed experimental results indicated that the relative superiority of Sb–SnO2/Ti over RuO2/Ti for treating the model substrates depended greatly on the employed supporting electrolytes, and that the superiority particularly vanished when NaCl was used as the electrolyte. Using this electrolyte, active chlorine species-mediated indirect reactions seemed to occur at both anodes, while in the Na2SO4 electrolyte, the surface-specific reaction occurred. Finally, surface analysis and diverse electrochemical experiments were performed to compare both anodes in a more quantitative way and to investigate the effect of the electrolytes on the electrocatalytic activities of the anodes.

Electron Transfer Process of Poly(ethylene oxide)-Modified Cytochrome c in Imidazolium Type Ionic Liquid

Abstract: Modification of cytochrome c (cyt.c) by poly(ethylene oxide) (PEO) chains enabled the protein soluble in 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ionic liquid without denaturation. However, as the solution was full of ions, suitable supporting electrolyte (KCl) was essential for the electron transfer reaction of cyt.c in the ionic liquid to attain adequate ion size for the active center.

Novel, reagentless, amperometric biosensor for uric acid based on a chemically modified screen-printed carbon electrode coated with cellulose acetate and uricase

Abstract: Amperometry in stirred solution has been used for the systematic evaluation of modified screen-printed carbon electrodes (SPCEs) with a view to developing a reagentless biosensor for uric acid. The developed system consists of a base cobalt phthalocyanine (CoPC) electrode tailored to the electrocatalytic oxidation of H2O2 by means of a cellulose acetate (CA)–uricase bilayer. Uricase was immobilized by drop-coating the enzyme onto the CA membrane covering the CoPC-SPCE. The device exploits the near-universal H2O2-generating propensity of oxidases, the permselectivity of the CA film towards H2O2 and the electrocatalytic oxidation of this product at the CoPC-SPCE. The electrochemical oxidation of the resulting Co+ species was used as the analytical signal, facilitating the application of a greatly reduced operating potential when compared with that required for direct oxidation of H2O2 at unmodified electrodes. The time required to achieve 95% of the steady-state current (t95iSS) was 44 s [relative standard deviation = 7.5%(n= 10)]. Amperometric calibrations were linear over the range from 13 × 10–6 to 1 × 10–3 mol dm–3, with the former representing the limit of detection. The CA membrane extended the linear range of the biosensor by over two orders of magnitude, when apparent Michaelis–Menten constants (Km′) of immobilized and free enzymes are compared. This suggests that the process is diffusion-controlled and not governed by the kinetics of the enzyme. The precision of electrode fabrication was determined by cyclic voltammetry to be 4.9%(n= 6). Successive amperometric calibrations (n= 7) over 7 d using a single sensor revealed only a 14.0% diminution in sensitivity from the original response. Sensor stability and the dependence of the steady-state current on the pH, ionic strength and temperature of the supporting electrolyte were studied and the results are presented. The functioning of the biosensor is indifferent to a wide range of potential interferences studied in a synthetic sample and results correlate favourably with those of a standard hospital method.