KCS

Direct electrochemical water splitting is a non-polluting way of producing pure hydrogen. Particularly, the products are free of CO, which is very beneficial in fuel cell applications. In the electrochemical water splitting, the obstacle would be an anodic reaction for oxygen evolution where substantial energy loss occurs mainly due to the high overpotential. Numerous electrocatalysts have been applied to reduce the overpotential in the water splitting including expensive precious metals (e.g. Ir, Ru, and Rh). In this study, we focused on the development of electrocatalyst with low cost ways: inexpensive material as well as low cost coating method. We demonstrate successful fabrication of Co3O4 electrocatalyst films at low temperature (50 oC) on a stainless steel substrate by a paste coating method using Nafion as a binder. The Co3O4 films were found to be catalytically efficient in water splitting reaction in an alkaline aqueous solution. In addition, we elucidated the relationship between the electrocatalytic activities and the particle size of Co3O4 in water splitting reaction. The details will be discussed in the presentation.