TiO
2-Ni composite electrodes were prepared by dispersion plating to make a photosensitive electrode with a high efficiency and ease of production. Composite layers of Ni matrix containing dispersed TiO
2 were deposited electrolytically on substrate metals from a Watts type nickel electrolyte containing the TiO
2 particles suspended in the solution. The electrodes were kept under 10
-5 Torr at 750°C for different periods to partially reduce TiO
2. The optimum time for the reduction was 15 to 30 minutes. A photovoltage vs. pH plot showed a linear relation with ΔE
photo/ΔPH=-60mV for the alkaline solutions investigated. From linear scan voltammograms, the dissolution of Ni matrix through the passivation layers was observed, even in alkaline solutions. A delay in the increase in the photovoltage was interpreted as photogenerated positive holes being consumed by the oxidation of water and Ni at the electrode interface. These composite electrodes showed the photovoltaic behavior similar to a TiO
2 single crystal electrode in alkaline solutions. In acidic solutions electrochemical dissolution of the Ni matrix increased.
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