Photocorrosion of plasmonic enhanced Cu_xO photocatalyst

The photocatalytic water splitting using Cu_xO film on metallic structures under visible light illumination is investigated. A plasmonic enhanced layer is applied for high efficient light harvest and to form a heterojunction to prolong the lifetime of the photogenerated electronhole pairs. Although Cu_xO is a potential photocatalyst with high efficiency, it suffers from serious photocorrosion. The photocorrosion mechanism of p-type Cu_xO has been investigated using x-ray photoelectron spectroscopy. Through analyzing the composition of Cu_xO during a photocatalytic water splitting reaction, it is found that the photocorrosion of Cu₂O on Pt is caused by the reduction of Cu₂O to Cu, while the photocorrosion of Cu₂O on Au is caused by the oxidation of Cu ₂O to CuO.