Vulcan Carbon as Support for Sputtered Oxygen Evolution Electrocatalysts

Abstract

The development of support structures for electrocatalysts has received a great deal of attention over the last decade, with carbon structures (i.e. nanostructures, Vulcan carbon (VC)) having been studied extensively. Carbon support structures increase the surface area, stability and activity of electrocatalysts in most cases, and can be used to overcome the delamination of thin films. In an attempt to (i) obtain surface structures and areas on SiO2 wafer pads, for combinatorial high-throughput sputtering and screening, that are comparable to glassy carbon (GC), (ii) eliminate delamination of the electrocatalyst and (iii) increase activity and stability, this study focused on VC:Nafion support preparation techniques. Four VC inks were prepared and used as carbon support on GC electrode inserts to analyse their effect on the activity of sputtered Ni thin films (40 nm) towards the oxygen evolution reaction (OER) in alkaline media. Linear sweep voltammetry (LSV) and chronopotentiometry (CP) were employed to compare the catalytic activity and stability of these sputtered Ni thin films on the various VC supports. Results suggest that similar activity compared with IrO2 and RuO2 could be achieved by sputtered Ni on VC:Nafion support, indicating improved Ni utilisation as well as improved short-term stability of the Ni thin films. These results validate the use of VC:Nafion support as substrate for sputtered electrocatalysts.