A novel electrolytic titrator design - Coating platinum cathodes with an electron sink using Nafion (R) and hexaammineruthenium (III)

作者：Gandhi Sahir Ilyas^*; Boutelle Martyn; O'Hare Danny^*

来源：Electrochemistry Communications, 2016, 73: 50-54.

DOI：10.1016/j.elecom.2016.10.013

• Electrolysis
• Hydrogen evolution reaction
• Nafion (R)
• Hexaammineruthenium (III)
• Titration

Water electrolysis produces a constant flux of H+ and OH-ions at the anode and cathode respectively. If the distance between the electrodes is reduced significantly, the pH gradients produced at the electrode surfaces become steep, and recombination of species is near instantaneous. In this experimental work, we show how microfabricated platinum cathodes coated with Nafion (R), and further loaded with hexaammineruthenium (III) (Ru(NH3)(6)(3+)) ions, can inhibit the production of OH-ions. Electrons from the cathode reduce Ru(NH3)(6)(3+) to Ru(NH3)(6)(2+) instead of water. Simultaneously, a constant flux of H+ ions from the un-modified anode, titrates the sample. The Nafion (R) film's coating, redox couple film loading, stability and pH related changes at the electrode surfaces, have all been studied. Crucial to the development of the electrolytic titrator, this research work shows the importance of crystalline ion-exchange membranes and an optimised method of loading them with redox couples.

• 出版日期2016-12