An apparatus for splitting water to produce hydrogen having at least one photoelectrochemical cell. The photoelectrochemical cell includes at least one water permeable photoelectrode having a light sensitive, nano-crystalline catalytic material layer, a polymer electrolyte membrane, a metallic substrate disposed between the light sensitive nano-crystalline catalytic material layer and the polymer electrolyte membrane adjacent to the polymer electrolyte membrane layer, and at least one photovoltaic device connected in series to the light sensitive nano-crystalline material layer and disposed between the light sensitive nano-crystalline catalytic material layer and the metallic substrate layer.