Cleavage of Water by Visible‐Light Irradiation of Colloidal CdS Solutions; Inhibition of Photocorrosion by RuO₂

The conversion of light into chemical fuels in photochemical devices equipped with semiconductor electrodes ( e.g. of n‐CdS) is associated with a serious problem: “holes” produced in the valence band of the semidonductor upon irradiation migrate to the surface where photocorrosion occurs. In mi‐croheterogenous CdS systems this is remedied by a thin layer of RuO 2 . A CdS sol prepared in the presence of maleic anhydride/styrene copolymer has now been loaded with RuO 2 and Pt; these CdS microelectrodes are surprisingly active catalysts for cleavage of H 2 O and H 2 S.