Electrodeposited p-type Cu2O as photocatalyst for H2 evolution from water reduction in the presence of WO3

Different P-type Cu2O powders were prepared from electrodeposition and subjected to analysis of their photocatalytic activity in water reduction. The electrodeposited Cu2O powders were obtained by scraping the deposited films off the substrate. Under illumination the Cu2O powders alone were not able to catalyze H-2. generation from water reduction. However, these Cu2O powders exhibited photocatalytic activity in H-2 generation when they were Coupled with n-type WO3 in suspensions. The coupling was made to avoid back reactions of the photo-induced charges. The electrodeposited Cu2O powders showed higher photocatalytic activity than a commercially available Cu2O powder. The suspension containing electrodeposited Cu2O With a strong [111] orientation gave a larger amount of H-2 evolution than that containing Cu2O with a [110] orientation. Appropriate crystalline-texture tuning, as well as charge delocalization promotion, is looked to as the key issue for efficient H-2 generation from water reduction over p-type Cu2O photocatalysts. (C) 2008 Elsevier B.V. All rights reserved.