Fig. 6.

Current density response of the photo-RRDE disk and Pt ring electrodes at pH 4.6, 20 mM acetate/acetic acid buffer (0.5 M LiClO₄) with assembly 1 on the surface of a 3.6-nm TiO₂ shell deposited by ALD onto a nanoATO-coated Ti disk electrode. The rotation rate of the RRDE electrode assembly was 500 rpm. The applied voltage at the disk was held at 1 V while the potential at the platinum ring electrode was held at −0.35 V for O₂ detection (V vs. Ag/AgCl 4 M KCl reference, 0.199 V vs. NHE); note ref. 24. Illumination was provided by the continuous output of a 473-nm DPSS laser (3.3 mW, LaserGlow model LRS-0473-PFM-00100-03). Light was cycled on or off through electronic TTL triggering of the laser.