Half-electrolysis runs one desirable half-cell reaction
with the
aid of a counter supercapacitor electrode which replaces the other
unwanted half-cell reaction occurred inevitably in conventional electrolysis.
Herein, it is developed to complete the whole cell reaction of water
electrolysis, in alternative steps, with a capacitive activated carbon
(AC) electrode and an electrolysis Pt electrode. When positively charging
the AC electrode, a hydrogen evolution reaction occurs at the Pt electrode.
By reversing the current, the charge stored in the AC electrode is
discharged to assist the oxygen evolution reaction on the same Pt
electrode. Consecutive completion of the two processes realizes the
overall reaction of water electrolysis. This strategy leads to stepwise
production of H2and O2without the need of
a diaphragm in the cell and hence results in a lower energy consumption
compared with the practical conventional electrolysis.