Tin oxide as stable protective layer for composite cuprous oxide water-splitting photocathodes. (June 2016)

• Record Type: Journal Article
• Authors: Azevedo, João; Tilley, S. David; Schreier, Marcel; Stefik, Morgan; Sousa, Célia; Araújo, João Pedro; Mendes, Adélio; Grätzel, Michael; Mayer, Matthew T.
• Is Part Of: Nano energy. Volume 24(2016:Jun.)
• Page Start: 10
• Page End: 16
• Publication Date: 2016-06
• Subjects: Water splitting -- Cuprous oxide -- Tin dioxide -- Stability -- Protective layer; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2016.03.022
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: For a sustainable future, efficient solar energy harvesting and storage is required. Solar hydrogen production from photoelectrochemical water splitting is a promising technology and, in particular, cuprous oxide photocathodes are interesting photoelectrodes due to their high efficiency and low cost. However, chemical instability inhibits practical application of such devices. This work reports a novel strategy for protecting cuprous oxide from photocorrosion, wherein a thin SnO2 overlayer enables increased stability over previous reports utilizing TiO2 protective layers. Performance and stability are influenced by the film thickness, post-deposition steam treatment, and the nature of the heterojunction interface. Stability over 57 h of sustained photoelectrochemical water reduction, maintaining 90% of initial photocurrent, is achieved. Highlights: Report a new protective overlayer for Cu2 O with enhanced chemical stability that should be broadly applicable to other photocathode materials. Optimized photocathodes were stable over 57 h of continuous illumination (twice as much as previous reported works), an important advance among Cu2 O-based devices. Studied influence of an interlayer of ZnO between Cu2 O and the protective layer and achieved improved onset potential. Applied a steam treatment, previously reported for TiO2, and here demonstrated that can be used for other materials with similar improvements.