Fig. S2.

(A) Current vs. time measurements as a function of the SnO₂ film thickness for FTO|SnO₂/TiO₂|–RuP²⁺/WOC with (black) 2.2 µm, (red) 4.1 µm, or (blue) 8.1 µm films. (B) Current vs. time measurements as a function of SnO₂ film thickness for FTO|SnO₂/AgNP/TiO₂|–RuP²⁺/WOC with (black) 2.2 µm, (red) 4.1 µm, or (blue) 8.1 µm films. The measurements were taken with an applied bias of 0.2 V vs. Ag/AgCl in 0.1 M HAc/Ac⁻ buffer at pH 4.65 with 0.4 M NaClO₄. Beginning in the dark,100-mW cm⁻² illumination was applied to the electrodes in 10-s intervals.