Preparation of p-Type CaFe2O4 Photocathodes for Producing Hydrogen from Water

An (hk0)-oriented p-type CaFe2O4 (E-g: 1.9 eV) photocathode was prepared, and hydrogen and oxygen gases were produced from a photocell short-circuited by connecting the CaFe2O4 and n-type TiO2 electrodes under illumination without applying an external voltage. The open-circuited voltage was 0.97 V and the short-circuit current was about 200 mu A/cm(2), and the amount of evaluated hydrogen and oxygen gases after 2 days of reaction were about 70 and 4 mu mol, respectively.