Catalytic Dipolar Multilayers of Graphene Oxide and Polyoxometalate on Hematite for Efficient and Stable Solar Water Oxidation

Abstract

Artificial photosynthesis has drawn great attention for decades as a promising solution to modern energy and environmental problems. Here, we report the development of an efficient and stable photoanode for solar water oxidation by layer-by-layer assembly (LbL) of cationic graphene oxide (GO) nanosheets and anionic molecular metal oxides (polyoxometalate, Co-POM). GO and molecular metal oxides were used as a charge-transporting layer and water oxidation catalyst, respectively, and deposited on hematite without alteration of their properties. It was found that their sequential deposition significantly improved the photocatalytic performance and stability of hematite. The present study demonstrates the validity of LbL techniques for the fabrication of electrochemical / photoelectrochemical devices and can provide a new insight for the design of novel devices.