Boron-Doped Diamond Dual-Plate Deep-Microtrench Device for Generator-Collector Sulfide Sensing

Abstract

A BDD-BDD dual-plate microtrench electrode with 6μm inter-electrode spacing is investigated using generator-collector electrochemistry and shown to give microtrench depth-dependent sulfide detection down to the μM levels. The effect of the microtrench depth is compared for a "shallow" 44 μm and a "deep" 180μm microtrench and linked to the reduction of oxygen to hydrogen peroxide which interferes with sulfide redox cycling. With a deeper microtrench and a fixed collector potential at -1.4V vs. SCE, two distinct redox cycling potential domains are observed at 0.0V vs. SCE (2-electron) and at 1.1V vs. SCE (6-electron).