A Versatile DIY Route for Incorporation of a Wide Range of Electrode Materials into Rotating Ring Disk Electrodes

Abstract

Rotating ring disk electrodes (RRDEs) are a powerful and versatile tool for mechanistically investigating electrochemical reactions at electrode surfaces, particularly in the area of electroanalysis and catalysis. Despite their importance only limited electrode materials (typically glassy carbon, platinum and gold) and combinations thereof are available commercially. In this work we present a method employing 3D printing in conjunction with machined brass components to produce housing which can accommodate any electrode material in e.g. pressed powdered pellet, wafer, rod, foil or vapor deposited onto a conductive substrate, form. In this way the range and usability of RRDEs is extended. This custom DIY approach to producing RRDEs, also enables RRDEs to be produced at a significant fraction of the cost of commercial RRDEs. To illustrate the versatility of our approach, co-planar boron doped diamond (BDD) RRDEs are fabricated for the first time, using the approach described. Experimental collection efficiencies for the redox couple FcTMA+/FcTMA2+ are found to be very close to those predicted theoretically. BDD electrodes serve as an ideal electrocatalyst support due to their low background currents, wide solvent window in aqueous solution and chemical and electrochemical stability in acid and alkali solutions. The BDD RRDE configuration is employed to investigate the importance of surface incorporated non-diamond carbon in BDD on hydrogen peroxide generation via the oxygen reduction reaction in acid solutions.

Real-Time Detection of Hydroxyl Radical Generated at Operating Electrodes via Redox-Active Adduct Formation Using Scanning Electrochemical Microscopy

“…Indeed, although we decided to use SECM because of its steadystate and imaging capabilities, short time scale for species detection, and previous experience in our laboratory with methods for ROS detection, 50 there is no reason why the presented methodology cannot be deployed using other techniques such as the rotating ring-disk electrode (RRDE), provided a suitable disk electrode is available. 63 Many laboratories in countries with limited resources may not have ESR instrumentation available, but it is common to find wellestablished electrochemical facilities elsewhere. Thus, we hope these findings will encourage more quantitative and informed mechanistic explorations of the role of • OH mediated oxidation processes on Fenton systems and on electrode surfaces.…”

Electron Paramagnetic Resonance for the Detection of Electrochemically Generated Hydroxyl Radicals: Issues Associated with Electrochemical Oxidation of the Spin Trap

“…The data suggested that quantification of the true concentration of OH • generated from water oxidation via EC-EPR is problematic. The use of different cell geometries, such as flow cells and/or rotating disk electrodes, 62 could be beneficial to minimize fouling events and prevent further oxidation of DMPO-OH • , as the product is swept away from the electrode surface. Further investigations are required.…”