Successive layers of Ag2O were applied in order to obtain a
sphere of material on the platinum wire (99.999%, Goodfellow, UK).
This sphere was then annealed in order to obtain Ag. Complete thermal
decomposition of the Ag2O to Ag and O2 occurs at 400 ◦C [13].
Both procedures used temperatures in excess of this value. For L2,
each electrode was annealed for 15 min at 450 ◦C. For N2, electrodes
were heated for 30 min at 100 ◦C (in order to first remove water
from the Ag2O paste) and then at 500 ◦C for 2 h.