WO 3 /Conducting Polymer Heterojunction Photoanodes for Efficient and Stable Photoelectrochemical Water Splitting.

An efficient and stable heterojunction photoanode for solar water oxidation was fabricated by hybridization of WO and conducting polymers. Organic/inorganic hybrid photoanodes were readily prepared by electropolymerization of various conducting polymers and co-deposition of tetraruthenium polyoxometalate (RuPOM) water oxidation catalysts (WOCs) on the surface of WO. The deposition of conducting polymers, especially polypyrrole (PPy) doped with RuPOM (PPy:RuPOM) resulted in a remarkably improved photoelectrochemical performance by formation of a WO/PPy p-n heterojunction and incorporation of efficient RuPOM WOCs. In addition, there was also a significant improvement in the photostability of the WO-based photoanode after the deposition of the PPy:RuPOM layer due to the suppression of the formation of hydrogen peroxide responsible for corrosion. We believe that the present study provides insight into the design and fabrication of novel photosynthetic and photocatalytic systems with excellent performance and stability through hybridization of organic and inorganic materials.