Figure 1.

Chronoamperometric testing of four a-TiO₂/Si electrodes in 1 M NaOH (aq.) under the illumination intensity of 1.00 Sun. Black: as-deposited film without post-treatment, blue: annealed at 400 °C, red: annealed at 500 °C, green: hydrogen treated for 10 min at 300 °C. The inset shows the photocurrent density of the as-deposited and 500 °C annealed samples during a long stability test under continuous irradiation. The photographs illustrate the surface at the end of the stability test. Photoanodes were kept at constant +1.23 V vs reversible hydrogen electrode (RHE).