the left-hand side, the photo-excited electrons reduce IO3
− back
to I−, while water is oxidized to O2 by holes. The proton generated
in the left-hand side is diffused to the right-hand side due
to concentration gradient. The redox mediators, I−/IO3
−, are circulated
between two sides via the Neosepta membrane. As shown in
Eqs. ((1)–(4)), after the reduction and oxidation of the redox mediators,
IO3
− and I− are counter-diffused toward the counter sides
due to the concentration gradients caused by the photoreaction.
Thus through this cycle, the mass and charge balances are maintained
when the generations of O2 and hydrocarbons are carried
out simultaneously in each side.