Electrochemical Properties and Range of Application of Mixed Gold Bismuth Electrodes

Electrochemical properties for mixed gold‐bismuth electrodes have been evaluated. Increased overpotential towards the hydrogen evolution reaction (HER) was found as a function of increased bismuth content in the gold‐bismuth mixture. Compared to a bare gold electrode, the overvoltage was increased by 80 mV for gold with 2% bismuth added (AuBi2), 170 mV for 6% bismuth added (AuBi6), and 580 mV for 25% bismuth added (AuBi25). Cyclic voltammetry (CV) in a NaOH solution was also carried out to study the formation of different oxide products on the surface. The practical use of such electrodes was demonstrated by differential pulse anodic stripping voltammetry (DPASV) for the detection of copper and mercury, and good linearity was found even for concentrations down to 0.25 μg/L. In addition to stability tests in NH4Cl, the analytical use and stability over time were evaluated in purified scrubbing water and polluted river water.