Projects per year
Tin-doped indium oxide electrodes are fabricated and employed in a dual-plate microtrench geometry with the inter-electrode gap controlling the mass transport conditions in generator-collector mode. Electrodes are fabricated with 2–50 µm gap sizes and variable trench depths by controlling assembly parameters. Non-ideal behaviour is observed for three aqueous redox systems: Ru(bpy) equation image, 1,1′-ferrocenedimethanol and Ru(NH3). Under fast mass transport conditions, the former two systems exhibit slower oxidation features. For Ru(NH3), non-steady-state behaviour is observed due to irreversible (ECirrev′) consumption of oxygen in the microtrench. A mechanism leading to hydrogen peroxide formation via superoxide in Ru(NH3) solution is proposed. Under optimised conditions all three redox systems provide reliable trench depth calibration information.