| Abstract
| - Thin silver chloride layers evolve oxygen under UV/vis illumination in aqueous solution under appropriateconditions. AgCl deposited on a conducting support photocatalyzes the oxidation of water to O2 in the presenceof a small excess of silver ions in solution. The light sensitivity in the visible part of the spectrum is due toself-sensitization caused by reduced silver species. Anodic polarization reoxidizes the reduced silver species.Considerable improvement of sensitivity has been observed with AgBr sensitized AgCl photoanodes. To testits water splitting capability, the AgCl photoanode was combined with hydrogen-producing semiconductors,such as a platinized silicon solar cell and platinized p-GaInP2. AgCl layers were employed in the anodic partand the H2 evolving semiconductors in the cathodic part of a photoelectrochemical cell for light-assistedwater splitting. The AgCl electrodes were characterized with surface photovoltage spectroscopy (SPS), whichidentified the transition from the valence band to silver cluster levels and by in-situ UV/vis diffuse reflectancespectroscopy, which detects the reduced and reoxidized silver species.
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