The electrolysis experiments were performed in a glass cell with a diameter of 6 cm, which was filled with 60 mL 0.01 M KOH electrolyte. The measurements were performed at room temperature. Electrolysis was performed by applying a voltage of 540 V or 300 V, between the Au POSC and a stainless steel plate counter electrode (15 mm × 20 mm × 3.5 mm). The distance between the working and the counter electrode was 2.5 cm. The Au wire on which the POSC was grown was capped with an Eppendorf pipette tip to have a defined surface area during the experiment. All measurements were performed without stirring the electrolyte. After each measurement, the electrolyte was exchanged, since the measurement can result in changes of the electrolyte temperature or electrolyte composition. The voltage was applied with either a TDK-Lambda Power Supply (630 V / 1.365 A) or a PlasmaTec Power Supply (Plasmatec Bias 1k015k NDCR1727F01002). In the former case the data was acquired with a LabView program. In the latter case the data was acquired using a Tektronix oscilloscope (Serial No. TBS1102B C013624, Voltage Range: 100-240 V (115 V); Frequency: 50-60 Hz (400 Hz), Power Max: 30 Watts). Both the Power Supply and a current probe (PICO TECHNOLOGY, TA189) were connected to the oscilloscope to read the applied voltages and the resulting currents. The data recorded with the current probe and the oscilloscope were subsequently smoothed.